Retreading - Goodyear Truck
Contents
1. 9L p 454209125 225 70R19 5 34155995 93 jJ 24570R19 5 f 38 5985 437509100 265 70R19 5 J 4750 105 e J J J 25570R225 5070 TIE FO 2457bR225 J JJ d amooo 26575R225 So J Jg g 4805910 290575R225 J J 5675 10 60050110 295 80R22 5 J J Jp HqJjJeeioe5 315 80R22 5 J JGcS J 76109120 77509120 p J w gt gt 285 75R245 T A d ersero X J JJ J Single Tire Load Rating EVEN NEN eee I 750oRIO0LT 24400660 27800680 LT225 7R16 2335065 2680060 p p j LT245 75R16 X 2628065 304227060 Q pf j LT215 85R16 2335065 2680080 p j __17235 85 16 2623965 304227060 dT 37500110 8 751657 23500665 2680080 M o j j 950RIC5L T 2780060 3170080 O 8R175 2835085 J ng D 85RI75 J 3 g 3195e902. J p bj ORI75HC 825R15 40708105 44100110 6005 125 loR1I75 J p JDJ94 46709110 k l 9 liR1I 5HC 1OO00RISTR J 50500105 55309120 69450125 8R195 23880080 3500110 _ w 9R225 825220 9 4900105 p pj 10R22 5 900R20 51500100 568098115 116225 1000820 S 6175 105 66100120 J 12R225 1100820 1 65900105 73900120 138225 o o o o 827100125 1 1 1200R20 82109120 1 1400R20 J l J DSO J J JJ 109600115 118245 1000822 64300105 70300120 12R245 1100802 9 q766090120 g 11 0024 23 5 3 4 o lDiiemonoaue a 88280010208 2159 75R1I75 J 2 J 48059125 p 225 70R19 5 36405 J A rl j 245 70R19 5 J 9 4080085 45450100 X 265 70R19 5 J J f 500010 A J
3. In Service Alignment Recommendations 49 37 Dos and Donts for Maintaining Proper Inflation Pressure 42 Nitrogen Inflation sss 42 Underinflation sss 40 103 Inspection Procedures 31 Installa 23 Loaded vs Unloaded Alignment Settings 45 Ebr IeablOPl casco rntatuseat tossed osen fucata 20 Matching of Duals 25 Minimum Tread Depths 104 Mixing Radial and Bias Ply Tires 96 Mounting and Inflation 29 Mounting Procedure 19 Assembly of Tire Tube Flap 22 Demounting sss 24 Inspection Procedures 31 Installation sse 23 TCA Du esti 20 Matching of Duals 25 Mounting and Inflation 29 BT E nieces 31 Proper Matching of Rim Parts 27 Safety Instructions 20 Safety 2 2 28 Servicing Tire and 31 26 Spacing of 26 Tire and Rim Cleaning 21 Tubeless Tire Mounting 23 Tubes and Flaps sss 22 Wheel Inspection Guidelines 20 Nail Hole Repair
4. Retreading SECTION ELEVEN Retreading INTRODUCTION Tire retreading is a manufacturing process Therefore any retreaded tire is only as good as the workmanship and the quality control in the plant that manufactured it To thoroughly evaluate a retread supplier one must look at both the product and service For these reasons a plant visit is important in the selection of a retreader PLANNING A RETREAD PLANT VISIT Prior to a plant visit a few items should be considered These may affect whether the retreader in question qualifies as a prospective supplier These considerations include 1 Does the retreader use quality products and procedures from a quality tread rubber manufacturer providing assistance to the retreader ie a Production associate training b amp technical assistance c Plant certification 2 Does the retreader offer any of the following services you may need Pick up and delivery of tires Flat repair National account program Tire mounting and demounting 24 hour road service s the retreader making repairs To both bias and radial casings To all types and levels of tire injuries spot repairs bead repairs reinforcements and section repairs 4 What is the retreaders turn around time Seven day turn around is typical 5 Does the retreader define warranty A PaO gU o E policy on both retreading and repairs Is there any casing warranty Wh
5. paCEersS n i 26 Spacing of Duals ciae tetendit 26 Speed and Tire Wear 57 Standards and Regulations 101 Commercial Vebicle Safety Alliance NAT eE 104 Federal Motor Carrier Safety Regulations 102 Federal Motor Vehicle Safety Standards Testing and Certification 102 Inspection sss 103 Minimum Tread Depths 104 Steer Axle Alignment 45 Steer Tire Wear 52 Tire and Rim Cleaning 21 Tire Description amp Specifications 76 Tire Industry Definitions 90 Tire NODIS see intet retta ierra 80 Application of Center Over Injury Section Repairs sss 85 Crown Repair 85 Nail Hole Repair Procedures 82 ERU EU 85 Radial Tire Section Repairs 84 tea Li Aime 84 Radial Section Repair Limits 84 Section Repair Limits in Sidewall and Shoulder Area 84 Tire Sealants And Balance Materials 100 Tire Selection amp Maintenance 70 Tire Selection Process 9 Tire Selection Process Work Sheet 16 Tire Siping Regrooving 105 Tire Siping for 105 DOT Regulations on
6. and the service conditions in which the tire is used customer considering siping tires should consult the new tire or retread rubber manufacturer to discuss appropriate siping machinery and techniques for the individual situation DYNAMOMETER TESTS Dynamometers are used by truck manufacturers and frequently by truck distributors or large fleet operators to test the engines and other parts of the driveline Dynamometer rolls vary in size from 8 5 8 inch to 50 inches The smaller rolls have a greater potential for damaging the tires During a dynamometer check there is little weight on the tires and only a small area of the tread face usually the center rib or center portion of the tread is in contact with the roll Excessive heat builds up in this small area If the test runs too long the excessive heat can damage the tire to the point where it could fail later on the highway The maximum safe time for running tires on a dynamometer roll varies with the roll diameter speed the power or torque transmitted from the tire to the roll and to some extent the load and inflation Figure 12 1 shows general rules for limiting the time for maximum power testing 50 60 MPH Time Limit at Max Power Roll Dia 20 nr 30 36 10 Min 48 50 15 Min Figure 12 1 For 50 percent power the time can be doubled For 25 percent power the time can be quadrupled 96 MIXING RADIAL AND BIAS PLY TIRES Due
7. 50 mph g 1 Tire loading restrictions for manufactured homes built before January 1 2002 Manufactured homes that are labeled pursuant to 24 CFR 3282 362 c 2 i before January 1 2002 must not be transported on tires that are loaded more than 18 percent over the load rating marked on the sidewall of the tire or in the absence of such a marking more than 18 percent over the load rating specified in any of the publications of any of the organizations listed in FMVSS No 119 49 CFR 571 119 S5 1 b Manufactured homes labeled before January 1 2002 transported on tires overloaded by 9 percent or more must not be operated at speeds exceeding 80 km hr 50 mph 2 Tire loading restrictions for manu factured homes built on or after January 1 2002 Manufactured homes that are labeled pursuant to 24 CFR 3282 362 c 2 1 on or after January 1 2002 must not be transported on tires loaded beyond the load rating marked on the sidewall of the tire or in the absence of such a marking the load rating specified in any of the publications of any of the organizations listed in FMVSS No 119 49 CFR 571 119 S5 1 b h Tire inflation pressure 1 No motor vehicle shall be operated on a tire which has a cold inflation pressure less than that specified for the load being carried 2 If the inflation pressure of the tire has been increased by heat because of the recent operation of the vehicle the cold inflation pressure
8. v 255 70R22 5 1 55109115 24575R225 JeMersseHo S Je 9 265 75R22 5 Jo S aono A p w 295 75R22 5 Jj 6ei75eii 0 66100120 V 295 80R22 5 o 1 373900115 315 80R22 5 8270120 90009120 po 1380R20 l 5 8050 110 1 14 80R20 o o 1 90909120 865 80R20 _ JA X 28575R245 jeeussenmo 9 9 385 65R22 5 98 70 120 425 65R225 1 500 110 445 65R22 5 TY 1238009120 Notes 1 With above loads and inflations the maximum speed is 65 MPH 55 MPH max 2 For ML tires see Tire and Rim Year Book for separate ML table 107 TRUCK TYPE AND WEIGHT CLASS The vehicle icons on the following page depict examples of vehicles in each DOT classification 1 8 with corresponding load ranges These classifications are guidelines in understanding the type of vehicle used for different applications by vehicle class CLASS ONE FISH rue PTSS AN 6 000 Ibs or less Full Size Pickup Mini Pickup Minivan Utility Van CLASS TYO psp FOA e HD HA 6 001 to 10 000 lbs 9 o 9o 9 o Q Q Crew Size Pickup Full Size Pickup Mini Bus Minivan Step Van Utility Van e 10 001 to 14 000 lbs City Delivery Mini Bus Walk In uson MES Ms NN 14 0
9. Bias Ply 72 Measured Sound Pressure Reference Sound Pressure The reference pressure is usually taken a the sound pressure at the threshold of hearing the d that can be heard 0 0002 200 _ Radial Cross Rib I Radial J Rib 100 68 70 Sound Level Decibels Bias Ply Production Cross Rib 4 microbar 74 76 78 80 Figure 12 2 Relative sound pressure vs sound level in dB A from SAE J57 tests Sound level units are measured in decibels abbreviated dB Since the human ear does not respond the same for all frequencies of sound the sound level meter has been modified to agree closely with the frequency response of the human auditory system When the frequency adjustments are included the suffix A is added to the dB unit dB A The relationship of sound pressure to sound level in the region caused by the tires of a truck is shown in a relative fashion by the curve in Figure 12 2 Note the relative increase in noise going from the relatively non aggressive radial rib tire to the bias ply rib tire to the radial cross rib to the bias ply cross rib tire Also note the nature of the curve wherein greater changes in sound pressure are required to cause a given change in sound level at the higher sound pressures than at the lower sound pressures 97 The data for the curve were obtained from standard SAE J57 tests using a truck with four test tires on drive axle and two rib tires
10. Nail Hole A penetration caused by a small sharp object 3 8 inch maximum diameter Outside Steam Bag A flexible bag usually reinforced used to encompass the tread and tire shoulders of a tire being retreaded or repaired Plies Layers of rubber coated parallel cords SECTION ELEVEN Retreading Protector Ply A ply added primarily for casing protection which in some cases may be removed during retreading Radial Tire A tire that has ply cords from bead to bead extending at about 90 to the centerline of the tread On top of the body plies are two or more belt plies of rubber coated cords extending approximately from shoulder to shoulder and running circumferentially around the tire at alternate angles at substantially less than the ply cord angle Reinforcement Repair Any material usually rubber and fabric vulcanized to a tire to add strength to the tire cord body at an injury Repairs to over 25 of plies usually require reinforcement Repairs of more than 75 of plies are usually called section repairs Repair Material Any rubber compound or patch material used to make repairs Repairing Reconditioning of portions of tires injured by punctures cuts breaks cracks etc These repairs restore strength for additional safe service See Reinforcement Spot Sections Nail Holes Retreading Recapping Full Treading Replacement of the worn tread with rubber extending ov
11. Procedures 82 Nitrogen Datlablog 42 sees tudo IUe etu UAE 97 Operation 31 Planning A Retread Plant Visit 87 87 Proper Matching of Rim Parts 27 Radial Ply 85 Radial Tire Section Repairs 84 Radial TCS RENTE 84 Radial Section Repair Limits 84 Radial Truck Tire 5 Cross Sectional View of Typical Tire 6 Radio Frequency Identification Tags 36 Radio Frequency Tag Usage 36 Regrooving lire Siping 105 Tire Siping for 105 DOT Regulations on Regrooved Tire 106 Labeling of Regroovable Tires 106 Retread Plant Inspection Checklist 92 109 Retreading 86 Definitions 90 Introduction sss 87 Planning A Retread Plant Visit 87 Plant Inspection sss 87 Retread Plant Inspection Checklist 92 Safety Instructions 20 Safety 28 Section Repair Limits in Sidewall and Shoulder Area 84 Servicing lire and Rim 31 Setback Steer 53 IE PEE muU PE ee REDE 95
12. Regrooved Tire 106 Labeling of Regroovable Tires 106 PC 46 Trailer Axle Alignment 49 Tube Flap Assembly 22 Tubeless Tire Mounting 23 Tubes and 22 40 Vehicle and Engine Design 64 Vehicle Operation 67 Wheel Inspection Guidelines 20
13. are also addressed Finally this section explains the variances in sound levels produced by radial truck tires and the conditions under which truck noise occurs 94 SECTION T weELVE USE OF CHAINS ON RADIAL TRUCK TIRES The use of tire chains can be helpful in providing additional traction in severe weather conditions such as ice and heavy snow especially when traveling in hilly or mountainous terrain Tire chains can be used safely and successfully with Goodyear radial truck tires provided several simple and important points are followed Always select chains that are specifically designed for radial tires These chains normally have shorter cross chains than older designs and allow the position of the side chains to be higher on the tire sidewall This is out of the high flex sidewall area of a radial tire and results in less susceptibility to sidewall damage Be sure to use the proper chain size for the tire on which it is being attached Tighten chains when they are first applied then after a short run in period readjust to ensure a continued snug fit on radial tires Serious sidewall damage may result from loose chains Check for adequate dual spacing especially if using single tire chains on each tire of a dual assembly The greater deflection of the radial tire may require more dual spacing in marginally spaced dual assemblies Finally always remove chains as soon as they are no longe
14. must be fresh Check the manufacturers date code or expiration date code on the container and ideally it should be stored in a cool dry area 5 With pre cure treads there should be no more than two splices per tire Observe the procedures and materials used for making tread splices for quality 6 Short tread pieces 18 or less should not be used to make splices 7 With pre cure tread application stitching must be performed in such a way as to eliminate trapped air pockets 8 Adhesive surfaces of tread rubber and cushion and the buffed surface of the tire must be kept free of contamination from hands and other sources Mold Cure Tread rubber is applied to the tire uncured The prepared tire is placed in a mold matrix which imprints the tread pattern as the rubber is cured directly on the casing Pre Cure The previously cured tread rubber with the tread design already formed is applied to the tire with a thin layer of uncured cushion gum on its base to serve as an adhesive The assembly is then placed in a heated pressurized chamber where the cushion gum is cured to both the tread rubber and the casing forming the bond between the two Time temperature and pressure are the three requirements of any retread cure system Increasing or decreasing any of these factors from an optimum level will affect such things as tread adhesion mileage and casing life The optimum time temperature specificatio
15. on steer axle The test consisted of a 50 mph coast by with microphone at 50 feet from the line of travel When several sources cause sound waves to impinge on the ear simultaneously the ear perceives the sum total of sound air pressure on the ear drum the pressures are additive However the sound level perceived by the overall auditory system is increased only according to the logarithmic rule demonstrated by the curve Therefore when sounds are emitted by various sources in a truck the combined effect can be obtained by adding sound pressures and then converting the total sound pressure to dB A If individual sources of sound have already been computed or measured in dB A the combinations of these sounds in terms of dB A cannot be obtained by addition of the individual dB A values Miscellaneous Miscellaneous SECTION E Typical sound levels of various over the road truck components and the effect on total sound level of combining these noise sources are shown in Figure 12 3 The tire noise value listed assumes the use of eight bias ply cross rib drive tires on the truck Speeds Above 35 MPH Six Predominant Noise Sources Intake 87 90 dB A Driveline 83 Tires 75 86 Figure 12 3 Combining noise sources Typical methods used to reduce truck noise to meet limits prescribed by law are as follows Reduce speed Retrofit equipment e Improve maintenance e Remove irregularly
16. referred to as Federal Motor Vehicle Safety Standards Those which cover over the highway usage and application are contained in Volume 49 of the same Code but in Parts 350 through 399 and are called Federal Motor Carrier Safety Regulations The differentiation between newly manufactured items and over the highway usage is quite clear Thus a tire manufacturer is concerned with complying with the Motor Vehicle Safety Standards regarding testing certification and markings while the owner or operator of a vehicle who is using the tires in service must be in compliance with the Motor Carrier Safety Standards in regard to the application usage and condition of those tires Standard 119 makes demands beyond simply testing For one thing the tire must carry a serial code of up to eleven digits or characters on one sidewall indicating the name of the manufacturer the producing plant the tire size the tire type brand name load range sidewall description etc and the week and year of production This information becomes especially important for record keeping and recall work For another the tire must carry information clearly molded into the sidewall to give the consumer a variety of facts about the product such as size type load range generic names of materials construction type whether for single or dual usage maximum load and inflation data and of course the DOT symbol and serial code The manufacturer mu
17. shall be estimated by subtracting the inflation buildup factor shown in Table 1 from the measured inflation pressure Table I Inflation pressure measurement correction for beat Minimum inflation pressure buildup Average speed Tires with Tires with over of tire in 4 000 Ibs 4 000 lb previous hour 1 814 kg 1 814 kg maximum load load rating rating or less 41 to 55 mph 5 psi 15 psi 66 to 88 5 34 5 kPa 103 4 kPa km hr 103 A regular program of tire inspection is essential for the prevention of rapid air loss failures At a minimum tires should be inspected at the time of the regular preventive maintenance checks The Bureau of Motor Carrier Safety recommends an inspection by the driver prior to every trip in its Truck Driver s Pre trip Check List n any tire inspection routine tires should be inspected for the following conditions If any are found the tire should be removed and repaired retreaded or scrapped as the condition indicates e Any blister bump or raised portion anywhere on the surface of the tire tread or sidewall other than a bump made by a repair These indicate the start of internal separation e Any cut that reaches to the belt or ply cords or any cut that is large enough to grow in size and depth e Any nail or puncturing object e If any stone or object is held by a tread groove and is starting to drill into the tread base remove the object Look for s
18. to deliver this report to the motor carrier upon his arrival at the car next terminal or to mail it to the carrier if he is not scheduled to be in a terminal within 24 hours after the time of the inspection The motor carrier then has 15 days from the inspection date to correct any violations or defects certify any action taken using Form MCS 63 and return the form to the BMCS office address indicated on the report Part 397 of the same regulation requires that for the transport of haz ardous materials vehicles equipped with duals on any axle must have the tires inspected every two hours or 100 miles whichever occurs first for the duration of the trip MINIMUM TREAD DEPTHS Minimum tread groove depths are specified for tire manufacturers under Federal Motor Vehicle Safety Standard 119 and for in use applications by Federal Motor Carrier Safety Regulations part 393 75 Under FMVSS 119 manufacturers must include tread depth indicators commonly called wear bars in six locations evenly spaced around the circumference of a highway truck tire so that they become visible when 2 32 of tread groove depth is remaining 104 COMMERCIAL VEHICLE SAFETY ALLIANCE CVSA Under FMCSR Part 393 75 operators are required to maintain at least 4 32 of tread groove depth on the front tires of any bus truck or truck tractor covered by that law and the standard 2 32 remaining tread depth on the other wheel posi
19. to differences in cornering force characteristics and spring rates the best tire and vehicle performance will be obtained by applying tires of the same size and construction radial ply bias ply to all vehicle wheel positions However different tire constructions are permitted on the steer drive and trailer axles of two axle tandem and multiple axle combinations when the following rules are observed Never mix different tire sizes or tire constructions on the same axle e f radial tires are mixed with bias tires the best handling will be obtained with the bias tires on the steer axle Dias or radial tires may be used on either axle of two axle vehicles providing the vehicle has dual rear wheels or is equipped with Super Single wide base tires e Either bias or radial tires may be used on the steering axle of vehicles with three or more axles Either all bias or all radial tires should be used on the nonsteering axles Never mix bias and radial tires in a tandem or multiple axle combination Always check with the vehicle manufac turer before changing tire size or con struction on any vehicle Carefully evaluate performance changes caused by tire size or construction changes before putting the vehicle back into service SECTION T weELVE NOISE Tires are one source of noise emitted by a truck operating at speeds above 35 MPH on a highway In addition to the tires other major sources of noise are E
20. to the thickness of tread compound between the bottom of the original tread grooves and the top of the uppermost breaker or belt The use of regrooving is more common in intra state bus service than in trucking fleets Goodyear recommends retreading radial tires for truck use rather than regrooving If retreading is not practical front tires can be regrooved and moved to trailers Drive tires should be taken off when about 80 percent worn the non skid depth increased by regrooving and then reapplied to the drive axle Regrooving requires probing the depth of the undertread so that a minimum undertread depth of 3 32 inch remain below the newly cut groove It is recommended that the local Goodyear representative be contacted for information if regrooving is being considered lire Siping For Traction Adding tire siping to new or partially worn rib tires for additional traction as differentiated from regrooving worn tread for additional mileage is an accepted practice for trucking fleets operating on and off the road Partially worn radial lug tires can also benefit from regrooving the tread pattern down to 80 of the deepest portion of the original non skid depth for added traction Standards amp Regulations DOT Regulations On Regrooved Tire Purpose and Scope This part sets forth the conditions under which regrooved and regroovable tires manufactured or regrooved after the effective date of the regulation may be so
21. 01 to 16 000 lbs C City Delivery Conventional Landscape Utility Large Walk In CLASS FIVE m Mia ee 16 001 to 19 500 lbs Bucket City Delivery Large Walk In CLASS SIX MEM Em ML Nl LL LLL PN 19 501 to 26 000 lbs Beverage Rack School Bus Single Axle Van Stake Body CLASS SEVEN EXEAT EE qu n 26 001 to 33 000 lbs E I City Transit Bus Furniture High Profile Semi Home Fuel Medium Semi Tractor ik in Refuse Tow NAVAN CLASS EIGHT en Sooo es 33 001 Ibs amp over Q o9 o Cement Mixer Dump Fire Truck Fuel Heavy Refrigerated Van Semi Tractor Semi Sleeper Tour Bus 9 TRAILERS BEER EU m A m Auto Transport Double Van Drop Frame Dry Bulk Dump Trailer Flatbed Flatbed Low Boy Logger Reefer Tanker Van Trailer 108 INDEX Ackerman Steering Effect on lire Wear 47 43 Ackerman Steering Effect on Tire War MENTRE 47 46 46 Drive Axle 48 In Service Alignment Recommendations 49 Loaded vs Unloaded Alignment SU M 45 Steer Axle Alignment 45 n 46 Trailer Axle Alignment 49 Bearing 55 Branding Tires 0 00 cee eee eee 35 Camber dev cea eerie stia erede bad rad 46 46 Ce
22. 6 2150965 24 0080 gt LT245 75RIG6 2381965 27 8080 Lr215 85RIO 2150965 24 0080 LI235 8BbRIG 2381965 27 8680 34159110 OT A J Jj j 5 9 50oR165T 2445065 27250080 o Ecc 2 um 5 mop OocoABl 3D le 9RI 5HC 825815 9 366098105 39700110 5675 125 1OR175 JJ S aooo d liR175HC 10 00R15TR 4430995 485090110 639590125 8 195 270080 J O 802 5 5 9 5 5 10R225 9 0020 48 59100 52500115 4 11R225 100020 5750 105 58000110 12R225 110000 _ 5780995 67509120 1382225 E PoC 12008200 c 72009110 J 01 0 116245 100082 60009105 61709110 EC uu X 9 9O 9X3 ABS 9 Jgozrm309 H0 J p j a J 9481000110 21575R175
23. a radial tire Rubber replacement only Stitching A method used to both remove trapped air and improve rubber contact for better adhesion Synthetic Rubber Man made rubber Texture See Buffed Texture Tread That portion of a tire that comes in contact with the road Tread Design The non skid pattern or design on the tread of a tire Tread Grooves The space between two adjacent tread ribs lugs or bars Undertread Replacement The rubber between the base of the tread groove and the buffed surface Vulcanization A chemical reaction which takes place under appropriate time temperature and pressure and develops desirable characteristics and properties See Cure Weather Checking Tire sidewall surface crazing or cracking attributable to aging and atmospheric conditions rather than to flexing Wicking A capillary action caused by fabrics or cords that allows air to escape from the tire casing or from under an envelope Retreading SECTION E LEVEN RETREAD PLANT INSPECTION CHECKLIST PLANT DATE INSPECTOR S NOT ACCEPTABLE ACCEPTABLE COMMENTS Plant Image A Appearance Space and layout Lighting Ventilation Production capacity Outside certification Material storage Evidence of training Casing Inspection A Lighting B Dry casings C Repairs removed D Casing D tracking Casing Repairing A Location and lighting Rep
24. air information procedures Material shelf life dates Material storage Single brand materials Repair I D Tool RPMs Buffing p Buffed dimensions profile Specification information Exposed cords finished Exposed cords cementing Texturize unbuffed areas Mold fit measurement Rasp condition smoking Buff texture Ta muaAs Handling cleanliness 92 SECTION ELEVEN Retreading ACCEP TABLE After Buff Preparation A Holes cuts probed B Buzz out limits Bias Radial C Cement application D Cement dry time Cement shelf life m Tread Application A Buzz outs filled B Tread rubber manufacturer brand grade C Spliced tread rubber 2 splices maximum minimum 120 spacing D Handling cleanliness A Thermocouple tests B Controls pressure temperature and time C Air steam leaks lire storage distortion free E Staples in tread of tire only Final Inspection A Lighting nspect on spreader Inspect hot Staples removed DOT serial number RAR identification m UO NOT ACCEPTABLE 93 COMMENTS Miscellaneous SECTION Miscellaneous The following section explains the use of chains on radial truck tires Chain use is designed to offer additional traction providing the chains and tires are matched appropriately for size and fit General precautions to tire siping dynamometer testing and mixing radial and bias ply tires
25. all products are compatible 5 The retreader should identify repairs Retread plant name date of repair etc 6 Check to see that the repair shop is using the proper RPM hand buffing tools a A high RPM grinder is used for grinding steel b Alow speed grinder is used on rubber Use of a higher RPM tool will scorch the rubber reducing adhesion Gummy rubber build up on buffing rasp and smoke generated at the buffed surface are indications of scorching Buffing The buffing operation is used to size shape and texturize the crown of the casing in preparation for the application of a new tread 1 All casings must be buffed to a predetermined Crown width Crown radius Specified remaining undertread Symmetrical profile Diameter and bead to bead dimensions in mold cure systems oce 2 Buffers should be computer or template controlled Buffer operators should not override computer programs or templates 3 Wall charts or other ready references should be in use to determine the correct specification for each tire as referred to above 4 All exposed cords fabric or steel must be finished to remove all fuzz and frayed ends 5 Allexposed cords fabric or steel should be coated with cement or other similar treatment promptly after completion of the buffing process Steel cords must be coated within 15 minutes 6 All untexturized areas such as tread grooves and irregular wear spots must be ha
26. bbles dimples or buckles are evident in the patch or tire liner 5 outside of the tire should be inspected for appearance 6 Allstaples must be removed from precure tread splices and wicking material 7 Check to see that the DOT identification number has been applied to the tire Ideally the DOT number should be located away from the bulge width of the tire so it will not be scuffed off in service 8 Allrejected returned as received RAR casings should have the rejection cause marked on the tire with the area of injury clearly identified 9 Finished retreads should be painted and all crayon marks should be painted over to give the final product an appealing appearance Retreading DEFINITIONS Base Width A measurement of that portion of the tread rubber that joins to the buffed surface of the worn tire Beads The anchoring part of the tire that is shaped to fit the tim Made of high tensile steel wires wrapped and reinforced by the plies Bead Sealing Area The flat area and heel area of the bead that contacts the rim With tubeless tires the bead area seals to the rim and rim flange to retain air Belted Bias Tires Tires constructed so the ply cords extend from bead to bead and are laid at alternate angles substantially less than 90 to the centerline of the tread On top of the body plies are two or more belt plies extending approximately from shoulder to shoulder running circumfer
27. ctured vehicles They set definite limits for total noise levels at various speeds and under stationary conditions The legislation for in service interstate motor carriers requires that overall external noise levels for trucks manufactured previous to the 1986 model year not exceed the following values measured at a distance of 50 feet from the vehicle centerline e 90 dB A on highways at speeds greater than 35 mph 86 dB A on highways at speeds of 35 mph or less 88 dB A during stationary runup at governed engine rpm 98 For trucks of 1986 model year manufacture and later the standard requires that the external noise level values must not exceed 87 dB A on highways at speeds greater than 35 mph 83 dB A on highways at speeds of 35 mph or less e 85 dB A during stationary runup at governed engine rpm New medium and heavy duty trucks vehicles with GVWR of 10 000 Ibs or greater must meet noise emission standards based on a vehicle acceleration and pass by test at speeds of up to but not exceeding 35 mph The noise measurement is taken at a distance of 50 feet from the centerline of vehicle travel and the test is performed by the vehicle manufacturer himself and certified to the EPA For medium and heavy duty trucks produced prior to January 1 1988 manufacturers had to test their vehicles to a maximum external noise level of 83 dB A For trucks manufactured after January 1 1988 the maximum e
28. d be under cover if possible Otherwise tires should be protected from elements by an opaque waterproof covering 3 f it is not possible to block up the vehicle inflation pressure in the tires should be increased to 2596 above the inflation required for the actual load on the tire in the storage condition 4 Vehicles should not be moved during extremely cold weather Under moderate temperature conditions vehicles may be moved if necessary Inflation in the tires must be adjusted to the recommended service pressure before shipping or putting a stored vehicle into service 6 Both tires and vehicles should be used on a first in first out basis to avoid excessive aging due to storage Based on varying weather conditions if tires are stored uncovered on vehicles under load some weathering may occur at approximately one year storage period A Miscellaneous S E CTION T W E LV E WHEN DOES THE WARRANTY END A tire has delivered its full original tread life and this warranty ends when the tread wear indicators become visible or five 5 years from he date of original tire manufacture or original new tire purchase date whichever comes first How Do I Know When My Tires Were Maufactured Tires with a Department of Transportation DOT number ending with 0100 or later were manufactured after 1 1 2000 0100 is the 4 digit production date in week week year year format 0100 means the tire was produce
29. d in the 1st week of 2000 Prior to January 2000 a 3 digit date code was used following a week week year format thus 019 means the tire was produced in the 1st week of 1999 TIRE SEALANTS AND BALANCE MATERIALS There are many vendors that sell aftermarket tire sealants and balance materials that can be added or pumped into a tire Goodyear does not endorse any product but if you wish to use such a product as either a sealant or tire balancer the Goodyear warranty is voided if the material adversely affects the tire inner liner 100 Standards amp SECTION THIRTEEN Regulations Standards amp Regulations Both truck tire manufacturers and truck tire users are covered by a number of federal and state regulations designed to assure the safety of the motoring public Some of the more important requirements of these regulations are discussed in the following section including Federal Motor Carrier Safety Regulations Commercial Vehicle Safety Alliance and Regrooving Tire Siping Regulations 101 Standards amp SECTION THIRTEEN Regulations FEDERAL MOTOR VEHICLE SAFETY STANDARDS TESTING AND CERTIFICATION The federal regulations which pertain to the performance and safety of truck tires fall generally into two categories Those regulations which affect the testing certification and marking of newly manufactured tires are contained in Volume 49 of the Code of Federal Regulations CFR Part 571 and are
30. ements shall not be made where tie bars humps or fillets are located c Except as provided in paragraph b of this section tires shall have a tread groove pattern depth of at least 2 32 of an inch when measured in a major tread groove The measurement shall not be made where tie bars humps or fillets are located d No bus shall be operated with regrooved recapped or retreaded tires on the front wheels e No truck or truck tractor shall be operated with regrooved tires on the SECTION HIR TE Standards amp N Regulations front wheels which have a load carrying capacity equal to or greater than that of 8 25 20 8 ply rating tires f Tire loading restrictions except on manufactured homes No motor vehicle except manufactured homes which are governed by paragraph g of this sec tion shall be operated with tires that carry a weight greater than that marked on the sidewall of the tire or in the absence of such a marking a weight greater than that specified for the tires in any of the publications of any of the organizations listed in Federal Motor Vehicle Safety Standard No 119 49 CFR 571 119 S5 1 b unless 1 The vehicle is being operated under the terms of a special permit issued by the State and 2 The vehicle is being operated at a reduced speed to compensate for the tire loading in excess of the manufacturer s rated capacity for the tire In no case shall the speed exceed 80 km hr
31. en the retreader has satisfied that it can meet the needs in these areas a visit to the plant for an evaluation of work methods and quality procedures is invaluable A plant inspection is divided into eight areas of concern They are in an order that should be convenient for a tour of the plant Many of the questions raised will not have absolute or totally objective answers Judgment and the retreader s response to questions will provide the answers needed to rate any individual retread plant t is suggested to reproduce the sections listed under Plant Inspection in this Recommended Practice for use in discussion with the retreader and its employees and also reproduce the Retread Plant Inspection Checklist appearing at the end of this Recommended Practice to use during a retread plant visit The checklist provides space to rate each item checked 87 PLANT INSPECTION Plant Image 1 Overall plant appearance should be clean and orderly 2 The plant must have adequate layout and space for effective handling of tires 3 The facility should be well lighted and adequately ventilated 4 The retread plant must have production capacity to handle your service needs 5 The retread plant should be inspected and certified by an industry association or supplier Casing Inspection The inspectors job is to determine whether the used tire is retreadable as presented If not the inspector will usually make recommendatio
32. entially around the tire at alternate angles Bias Ply Tires Tires constructed so the ply cords extend from bead to bead and are laid at alternate angles substantially less than 90 to the centerline of the tread Body Plies Layers of rubber coated parallel cords extending from bead to bead Breaks Cracks A surface opening extending into or through the plies Flex Breaks A break into or through one or more plies usually parallel to the beads Impact Breaks A star or X shaped or diagonal break into or through plies usually visible from the inside of the tire Radial Crack A crack in the outer surface of the tire usually in the sidewall area proceeding perpendicular towards the bead Tread Cracks Channel or Groove Cracks in the base of the tread grooves or voids Buckled Any gross distortion of the tire body or tread area evidenced by wrinkling on the inside of the casing Buffed Contour The shape of the buffed tire that usually includes a specified radius and width Buffed Radius A measure of the buffed surface curvature from shoulder to shoulder Buffed Texture That surface produced by buffing rasping or cutting as defined by The Rubber Manufacturers Association Buffed Textures RMA Shop Bulletin No 29 www rma org Casing The complete tire structure Cement An adhesive compound used to provide building tack May be brushed or sprayed on t
33. er the shoulders Top Treading Replacement of the worn tread area only Bead To Bead Retreading Replacement of the worn tread area and sidewall rubber extending to the bead Precured Tread Retreading Replacement of the worn tread areas with pre vulcanized treads containing the tread design already cured in Sections Reinforced repairs made to a casing where an injury larger than a nail hole extends through more than 75 of the plies or through the casing in the tread or sidewall areas Separation Lack of adhesion or cohesion between any adjacent materials in a tire Tread Separation Pulling away of the tread from the tire body Retread Separation A separation between the tread rubber and the buffed tire casing Ply Separation A separation between adjacent layers of cords plies Bead Separation A breakdown of the bond between components in the bead area Belt Edge Separation A breakdown of the bond between components near the edge of the belt plies Shoulder The upper sidewall areas of the tire casing immediately adjacent to the tread area Sidewall That portion of the tire casing between the tread and bead Skive Removal of damaged material prior to making a repair 91 Splices A junction of the ends of any tire components Spot Repair The replacement of rubber only in an injury that penetrated to no more than 25 of the body plies in
34. ference Less than 1 32 inch tread depth at two adjacent major tread grooves at three separate locations on tire With duals both tires must have listed defect to warrant out of service judgement Tire flat or has leak that can be felt or heard Bias ply tire with more than one ply exposed in tread area or sidewall or when exposed area of top ply exceeds 2 square inches With duals both tires must have listed defect to warrant out of service judfgement Radial tire with two or more plies exposed in tread area or damaged cords evident in sidewall or exposed area on sidewall exceeding 2 square inches With dual both tires must have listed defect to warrant out of service judgement Bulge suggesting tread sidewall separation Exception Bulge from section repair sometimes identified by adjacent blue triangular label is not a defect unless higher than 3 8 inch Mounted or inflated so tire contacts part of vehicle or in the case of a dual assembly its mate Tire overloaded including overload resulting from under inflation Exception Does not apply to special permit vebicle operated at a speed low enough to compensate for underinflation 105 TIRE REGROOVING SIPING Regrooving is used in certain types of service to extend the mileage obtainable from the original tire tread Tires designed with sufficient undertread depth to permit regrooving are labeled on the sidewalls as regroovable Undertread depth refers
35. he buffed surface Check Template A precut pattern used to determine the contour of a buffed tire to check compatibility to a matrix Cords The individual strands forming the plies in a tire Cross Section The section width of a tire casing Cure The process of vulcanization of rubber by applying heat and pressure for a specified time Curing Tubes Special tubes placed within the tire while curing Diaphragm A flexible sheet used to encompass part or all of a tire during 90 retreading in some processes Gauge Thickness usually expressed in thirty seconds of an inch by the decimal system or in millimeters in the metric system Injuries A break or cut of any shape caused by a penetrating object or severe scuff or impact Injury Size Widest opening in the cord body after skiving and buffing Inner Liner The tubeless tire inner surface used to retain the inflation media Kinked Beads A sharp permanent bend in the bead wires at one or more points around the circumference of the bead Load Range Specified as a letter A B C etc to identify a given size tire with its load and inflation limits when used in a specific type of service as defined in Tire and Rim Association Inc or equivalent yearbooks Matrix Aluminum rubber or steel rings or segments that form the cavity in which a tire retread is cured and with which the tread design is formed
36. he rubber deeply The severity of the oxidation is of course a time and temperature dependent variable Long term storage at ambient temperatures have been equated to short term storage at elevated temperatures For instance three days storage at 158 F causes approximately the same loss in tensile strength as three years storage at 75 Oxidation may cause sufficient damage to the inside of an unmounted tire as to cause early tube failure or a slow leak 4 Undue Stress in Storage If possible tires should be stored vertically on treads Severely stressed and distorted tires are subject to much greater damage from solvent ozone or oxidative attack than those which are not stressed or are stressed minimally and uniformly Unmounted tires stacked horizontally on sidewall should be piled symmetrically and never so high as to cause severe distortion to the bottom tire Tires that are mounted on rims but not on vehicles should follow the same recommendations as for unmounted tires 5 Foreign Material Dirt Water Unmounted tires should be stored under a waterproof covering Dirt is not harmful to a tire However dirt on the inside of a tire placed in service can cause early tube failure or a slow leak Water on the inside of a tire in service can be turned into steam which can quickly destroy the strength of both the rubber and the textile members of the tire Additionally water and dirt inside a tubeless tire can cause c
37. he tire cord material shall not be damaged as a result of the siping process and no sipe shall be deeper than the original or retread groove depth B Siped regroovable tires No person shall sell offer for sale or introduce for sale or deliver for introduction into interstate commerce a regroovable tire that has been siped by cutting the tread surface without removing rubber if the tire cord material is damaged as a result of the siping process or if the tire is siped deeper than the original or retread groove depth Labeling of Regroovable Tires Each tire designed and constructed for regrooving shall be labeled on both sidewalls with the word Regroovable molded on or into the tire in raised or recessed letters 0 025 to 0 040 inch The word Regroovable shall be in letters 0 38 to 0 50 inch in height and not less than 4 inches and not more than 6 inches in length The lettering shall be located in the sidewall of the tire between the maximum section width and the bead in an area which will not be obstructed by the rim flange See Page 102 Subpart G Miscellaneous Parts and Accessories for the Federal Motor Carriers Safety Regulatons regarding regrooved tires LOAD RATINGS AND INFLATION DATA FOR RADIAL TRUCK TIRES Tube Type Load Range Load Range Load Range Load Range Load Range Load Range Load Range Dual Tire Load Rating 7 50R16LT 21409065 22720080 S LT225 75RI
38. ing service and tire application Specifically siping may help reduce irregular wear on trailer axles where light one way loads are encountered such as grain trailers or belly dumps that operate under extreme load variations from unloaded to loaded conditions 95 On the other hand siping is generally believed to detract from treadwear on lug type tires used on drive wheel position This is because siping tends to break up the tread pattern and cause increased bending of the tread elements This results in faster wear due to increased scuffing as the tire goes through its footprint under torque The effect tread siping has on tire performance can vary considerably with the particular tire pattern being siped For example in a heavily bladed tread pattern it is believed that siping in the original tread state could hurt treadwear Other tread patterns such as those having a much higher net to gross footprint area might be more adaptable for siping under the service conditions discussed earlier f a customer chooses to sipe his Goodyear tires we strongly recommend that he pay close attention to the type of siping used Specifically our experience is that siping should be performed laterally across the tread although angles that vary somewhat from this might also be acceptable However to the best of our knowledge siping that is more or less circumferential has not been demonstrated to be successful Also our experience
39. kid spots and irregular wear conditions and refer to the chapter on alignment irregular wear and rotation The owner or operator should also be aware that the use of recapped retreaded or regrooved tires is restricted by the BMCS Federal Motor Carrier Safety Regulations and some state regulations and that the Rubber Manufacturers Association recommends against their use in certain applications n addition to the routine type of common sense owner performed tire inspection just described there are mandatory inspections which involve agents and agencies of the federal government For example the inspection of tires for defects is required by NHTSA Vehicle In Use Inspection Standards and by BMCS Federal Motor Carrier Safety Regulations Part 396 of the Federal Motor Carrier Safety Regulations authorizes special agent personnel of the Federal Highway Standards amp SECTION THIRTEEN Regulations Administration including Bureau of Motor Safety inspectors to perform inspections of a motor carriers vehicles which are currently in operation These inspections may be performed at a facili ty of the motor carrier such as a termi nal or at some other location such as on highway at the discretion of the inspector The results of these inspec tions are recorded in a Driver Equipment Compliance Check report If the check is done at a location other than one of the motor carriers facilities the driver is required
40. ld offered for sale introduced for sale or delivered for introduction into interstate commerce Definitions A Regroovable tire means a tire either original tread or retread designed and constructed with sufficient tread material to permit renewal of the tread pattern or the generaton of a new tread patternin a manner which conforms to this part B Regrooved tire means a tire either original tread or retread on which the tread pattern has been renewed or a new tread has been produced by cutting into the tread of a worn tire to a depth equal to or deeper than the molded original groove depth Applicability A General Except as provided in paragraph B of this section this part applies to all motor vehicle regrooved or regroovable tires manufactured or regrooved after the effective date of the regulation B Export This part does not apply to regrooved or regroovable tires intended solely for export and so labeled or tagged Requirements A Regrooved tires 1 Except as per mitted by paragraph A 2 of this sec tion no person shall sell offer for sale or introduce or deliver for introduction into interstate commerce regrooved tires produced by removing rubber from the surface of a worn tire tread to generate a new tread pattern Any person who C T ION regrooves tires and leases them to own ers or operators of motor vehicles and any person who regrooves his own tires for use on motor vehicles is co
41. n is determined by completing a thermocouple test in that particular curing equipment a Check to see if the retreader has had thermocouple tests made in his equipment b Ask to see what control systems or procedures are used to ensure that all tires are cured at the correct temperature pressure and time period All envelopes diaphragms and curing tubes must be leak free Check for steam and air leaks which may contribute to improper cure Tires must be stored in such a manner as to avoid distortion of the tread and or casing before curing and immediately after Wicking material used with pre cure systems must not be stapled into the tire sidewall or bead Sidewalls and beads are not designed to accept 89 from staples can allow moisture to enter and create rusting of the steel body in steel cord tires Final Inspection amp Finish After curing a final inspection should be made of the finished retread At this time the finished tire may be trimmed of rubber flashing or overflow painted and tagged for delivery 1 The inspection area must be well lighted 2 The tire must be inspected on a spreader 3 tis recommended that tires be inspected immediately after completion of the cure cycle while still hot Separations and other flaws that are visible while hot may disappear as the tire cools 4 The inside of the tire must be inspected to ensure that all patches are properly bonded and that no bu
42. nd treated to remove oxidation and surface dirt 7 Buffing rasps should not be smoking excessively This would be an indication of scorching and will result in poor adhesion 8 Buff texture must be consistent with Rubber Manufacturers Association www rma com guidelines See the RMA buffed texture chart 9 Buffed tires must be handled in such a way as to ensure the buffed surface is not contaminated 88 After Buff Preparation tems listed in this category include a number of interim steps between the major operations of buffing and tread application Depending upon individual retread plant procedures these steps might be performed individually or as part of the repairing buffing or tread application steps 1 An after buff inspection should be performed to ensure the buffing process has not uncovered any previously unnoticed defects 2 All holes cuts and penetrations must be probed to determine the severity of the injury and to ensure that all foreign material has been removed 3 Buzz out skive out Note that this is the single most neglected or mishandled detail and one of the major causes of retread failures All dirt rust and foreign material must be removed all separated and or laminated rubber must be removed leaving a clean solid surface for the filler material to adhere to Any buzz out that exceeds the specified limits must be treated as a section repair 4 Tires must be measured for
43. ngine e Radiator fan Engine exhaust e Engine air intake e Driveline e Aerodynamics wind noise Noise is defined as a disagreeable sound Pressure waves in the air produce sound The human ear is designed to sense these pressure waves and transmit signals to the brain indicating the magnitude and characteristics of the sound The ear mechanism can detect very faint sounds with very low air pressure energy levels and yet can detect and withstand relatively loud sounds with high energy levels without becoming damaged To accomplish this wide range of hearing the ear mechanism brain response is not directly proportional to the sound pressure but is less sensitive at the louder end of the range The total noise output of a truck is usually measured with an instrument called a sound level meter The input to the sound level meter is through a microphone that is placed nominally 50 feet from the center of the highway lane that is being monitored The sound level meter has electronic circuitry designed to approximate the human auditory system Thus the input is varying air pressure caused by the sound through a microphone and the output is a value indicated on a scale that gives the sound level of the noise The sound level or more precisely the sound pressure level indicates the degree of loudness to the human ear of a given sound Sound Level 20 Note quietest sour of pressure
44. ns as to the disposition of the used tire scrap repair and then retread return to the customer for adjustment consideration etc The ability to analyze worn and damaged tires is a skill usually acquired through experience and also requires a working knowledge of all the various steps of the retread process Look for an experienced person in this position 1 Inspection area must be well lighted 2 Tires must be dry before being inspected 3 Check to see whether the retreader is using any electronic ultrasonic or other high tech inspection equipment 4 Check the retreader s system of tracking casings in process to ensure that all of your casings get back to you and that they are returned on schedule Retreading Casing Repairing The repair persons job is to make structural repairs to damaged areas of the casing so the casing will be sound enough to last through a new tread life 1 Aseparate clean well lighted area should be used for the repair area 2 Wall charts should be posted showing procedures patch usage cure times etc Retreaders recommendations and procedures must be followed 3 Repair materials must have current manufacture date codes or expiration date codes Most repair materials have a shelf life and ideally should be stored in a cool dry place 4 All repair materials cements and supplies should be from the same manufacturer It is a questionable practice to mix brands since not
45. nsidered to be a person delivering for introduc tion into interstate commerce within the meaning of this part 2 A regrooved tire may be sold offered for sale or introduced for sale or delivered for introduction into interstate commerce only if it conforms to each of the following requirements a The tire being regrooved shall be a regroovable tire b After regrooving cord material below the grooves shall have a protective covering of tread material at least 3 32 inch thick c After regrooving the new grooves generated into the tread material and any residual original molded tread groove which is at or below the new regrooved depth shall have a minimum of 90 linear inches of tread edges per linear foot of the circumference d After regrooving the new groove width generated into the tread material shall be a minimum of 3 16 inch and a maximum of 5 16 inch e After regrooving all new grooves cut into the tread shall provide unobstructed fluid escape passages and f After regrooving the tire shall not contain any of the following defects as determined by a visual examination of the tire either mounted on the rim or dismounted whichever is applicable 1 Cracking which extends to the fabric ii Groove cracks or wear extending to the fabric or iii Evidence of ply tread or sidewall separation 106 THIRTEEN g If the tire is siped by cutting the tread surface without removing rubber t
46. nter Over Injury Section Repairs 85 Chains on Radial Truck Tires 95 Collecting and Storing Tire Infos HOEE 35 Branding Tires sss 35 Radio Frequency Identification Tags sss 36 Radio Frequency Tag Usage 36 Commercial Vehicle Safety Alliance CVSA ee iin 104 Cross Sectional View of Typical Tire 6 Crown Repair Limits 85 Demounting 24 Drive Axle Alignment 48 Drive Tires 54 Dynamometer 96 Factors Affecting Ireadwear 50 Bearing Adjustment sss 55 Drive Tires 54 Environmental 1 56 How Speed Affects Tire Wear 57 Setback Steer 1 53 Steer Tire 52 Factors Affecting Truck Fuel Economy 63 ADVI EE RR 78 Environmental Conditions 74 77 Tire Description and Specifications 76 Tire Selection and Maintenance 70 Vehicle and Engine Design 64 Vehicle Operation 67 Federal Motor Carrier Safety Regulations 102 Federal Motor Vehicle Safety Standards Testing and Certification 102
47. orrosion to tubeless rims and plug tubeless values both a source of potential tire failure Foreign material on the tire bead seat could affect air seal and cause air loss 6 Inflation If tires are mounted on rims and inflated pressure should be maintained at 10 PSI If tires are inflated and put in storage during warm weather the initial inflation should be about 15 PSI to offset the drop in pressure which will occur during the cold weather months 7 Protective Cover If tires are stacked first lay a foundation of clean wood to protect them from dirt oil grease etc Tires should be covered with an opaque or black polyethylene film PVC or any other clear film is not satisfactory The polyethylene film will protect against ozone generated by 99 electrical sources and cut down on air circulation which will minimize both the available oxygen and ozone which degrade rubber 8 Do Not Use Paint to Preserve Tires For Tires Installed on Vehicles 1 The storage area surface under each vehicle should be firm reasonably level well drained and free of all oil fuel or grease Clean 1 4 3 4 gravel under each tire is desirable if the area is not paved Storage should not be permitted on blacktop or oil stabilized surfaces 2 When storage longer than 6 months is anticipated the vehicle should be blocked up so weight does not rest on the tires and inflation pressure reduced to 15 PSI Storage of such vehicles shoul
48. proper mold fit or tread length in the case of some pre cure methods Cement is used to enhance the adhesion between the new tread and the prepared casing a The tire should be clean before cementing b Adequate drying time must be allowed prior to tread application c Cement container must be protected from air supply line moisture and oil contamination d Check manufacturer s date code or expiration date on cement container Cements have a shelf life and must be kept fresh e The in use cement container must be kept mixed while being used to eliminate the possibility of solid settling out from the mixture Retreading ELEVEN SECTION Curing There are two popular cure systems Tread Application Tread application is the fitting of staples Staples may penetrate the tubeless liner creating air leaks Holes new tread rubber which will become the new tread onto the prepared casing This rubber must be the correct width and thickness It must be centered and it must be circumferentially consistent 1 All buzz outs should be filled flush with the buffed surface 2 All exposed cord fabric or steel should be covered with cushion gum before the tread rubber is applied 3 Check to see what brand product line and grade of tread rubber is being used It is the retreader s responsibility to notify his customers if this specification is changed 4 Raw materials tread rubber cushion etc
49. r needed TIRE SIPING Tire siping is a process of making small knife like slits in the tread rubber surface Normally this is accomplished by a machine that uses sharp highspeed rotating discs to make cuts that are at an angle of 90 to the circumference of the tread Siping cuts are normally controlled so they are spaced a specific distance apart from one another They also will vary in depth across the tread face Proponents of tread siping have claimed various performance improvements for truck tires These claims include improved treadwear and reduced irregular wear Also it is often claimed that siping improves traction for winter and wet driving conditions on certain road types At present the majority of truck tire siping is done in the westernmost Midwest states and the Northwest corridor It is popular in certain areas and especially during the winter months to sipe both steer and drive and sometimes trailer tires Goodyear position on siping is that it may under certain operating conditions improve tire performance However under the vast majority of truck operating conditions new tires are designed and produced with tread patterns and tread compounds that do not require tread siping to give satisfactory performance Actual testing indicates that siping may improve the tire s resistance to irregular wear on free rolling wheel positions that are susceptible to irregular wear due to the combination of operat
50. re legally sold for over the highway use in the U S it becomes essential for a manufacturer to test and certify his tires to Motor Vehicle Safety Standard 119 The other Federal Motor Vehicle Safety Standard which effects truck tires is FMVSS 120 which spells out tire and rim selection and matching requirements for vehicle manufacturers This standard is intended to ensure that when a consumer purchases a new vehicle the total maximum load capacities on any axle are at least as great as the gross weight rating of that axle so that the load carrying capacity of the tires is not exceeded so long as the vehicle is properly loaded 102 Federal Motor Carrier SAFE IY REGULATIONS TITLE 49 CODE OF FEDERAL REGULATIONS PARTS 40 325 383 385 386 387 390 397 399 U S DEPARTMENT OF TRANSPORTATION FEDERAL HIGHWAY ADMINISTRATION SEPTEMBER 1993 American Trucking Associations SUBPART G MISCELLANEOUS PARTS AND ACCESSORIES 393 75 Tires a No motor vehicle shall be operat ed on any tire that 1 has body ply or belt material exposed through the tread or sidewall 2 has any tread or sidewall separation 3 is flat or has an audible leak or 4 has a cut to the extent that the ply or belt material is exposed b Any tire on the front wheels of a bus truck or truck tractor shall have a tread groove pattern depth of at least 4 32 of an inch when measured at any point on a major tread groove The measur
51. s and warning wheels and tires Vehicles which pass the inspection are issued a CVSA decal colored differently for each quarter of the year and honored for the month of issuance plus the SECTION THIRTE Standards amp Regulations N following two months by all participating states and provinces Criteria for the tire inspection portion of the CVSA inspection program recommends replacement of a tire with any of the following conditions Steering Axle of Power Unit Less than 2 32 inch tread depth at two adjacent major tread grooves anywhere on the tire Portion of breaker strip or casing ply visibe in tread e Sidewall is cut worn or damaged thereby exposing ply cord Labeled Not for Highway Use or other marking excluding current application Excluding farm off road vehicles briefly on the road e Bulge suggesting tread sidewall separation Exception Bulge from section repair sometimes identified by adjacent blue triangular label is not a defect unless higher than 3 8 inch e Tire flat or has leak that s felt or heard e Mounted inflated so tire contacts part of vehicle e Tire overloaded including overload resulting from under inflation Exception Does not apply to special permit vebicle operated at a speed low enough to compensate for underinflation Drive Trail Tires Out of Service 75 percent or more tread width loose or missing in excess of 12 inches of tires circum
52. shows that siping with varying depth across the face of the tread usually yields better results than constant depth siping This also appears to provide the minimum risk for increasing the tire s susceptibility to tread rubber chunking t is important to note that the Goodyear warranty provides protection for the user against failures from workmanship or material conditions f a tire failure occurs because of a condition beyond Goodyear s control such as siping the warranty is null and void Miscellaneous Miscellaneous S EC TION E n recent years a number of retread rubber manufacturers have produced precure tread rubber that is siped when molded Various claims of improved treadwear fuel economy etc have been made Our experience indicates that while these claims may be true in specific instances it is largely a matter of siping the tread in such a way that is compatible with the particular tread rubber compound and tread pattern design being used n other words if tread siping is considered an integral part of the manufacture of new tread rubber at the outset the siping can be more or less customized to the type of rubber and type of pattern so that performance can be optimized n summary tire siping may have certain performance advantages in improved treadwear and or traction however these can be expected to vary considerably depending on the particular type of tread rubber the tread pattern
53. st also include treadwear indicators evenly spaced around the circumference of the tire to indicate visually when the tire has worn to a tread depth of 2 32 The regulations encompassed by the Federal Motor Vehicle Safety Standards for newly manufactured products are administered by the National Highway Traffic Safety Administration NHTSA a branch of the U S Department of Transportation DOT Those laws contained within the Federal Motor Carrier Safety Regulations are administered by the Federal Highway Administration FHWA also a branch of the DOT and enforced by the Bureau of Motor Carrier Safety BMCS a sub agency of the FHWA and one of the few true enforcement arms within the DOT Part 571 119 of Volume 49 of the Code of Federal Regulations known as Federal Motor Vehicle Safety Standard 119 FMVSS 119 requires that a variety of tests be performed by a tire manufacturer to certify that a specific size of a tire line meets Federal safety requirements The main purpose of this law is to ensure tire testing and certification to specific performance parameters in the areas of endurance and strength By randomly sampling and laboratory testing tires in this manner during production periods a tire manufacturer certifies that his product meets the minimum safety requirements established by law He also properly qualifies his tires to carry the stamping on the sidewall Since this DOT marking must appear on any ti
54. tions n conjunction with the federally required tire inspections previously mentioned much work has been done to promote commonly performed and recognized tire inspection criteria within the scope of the total vehicle inspection program in use by the Commercial Vehicle Safety Alliance CVSA The CVSA is a voluntary organization made up of states and provinces which have responsibility for commercial vehicle safety operations and which perform vehicle inspections and conduct other safety related programs The aims of the organization are to maximize the utilization of commercial vehicle driver and cargo inspection resources to avoid duplication of effort to expand the number of inspections performed on a regional basis to advance uniformity of inspection and to minimize delays in industry schedules which could result from this type of enforcement activity The CVSA does not supersede or countermand any legally required inspection process or any state laws t is simply a working agreement among member jurisdictions to use standardized procedures It has gained widespread acceptance and has made great progress toward providing a common inspection program CVSA members inspect vehicles on highway and in terminals Areas covered by a CVSA vehicle inspection are the driver license hours of service records medical certificate steering mechanism brakes brake lights turn signals drawbars suspension fifth wheels air los
55. worn tires Restrict lug tires to drive axles Use radial tires on all axles Use rib tires on all axles e 87 90 dB A Laws on noise are established by the Federal government and are administered by the Environmental Protection Agency EPA Active enforcement however generally is the responsibility of state highway authorities Since the enactment of the Noise Control Act of 1972 the EPA has been empowered to issue regulations controlling the operational noise levels of interstate rail and common carriers and the noise emissions of newly manufactured products To do this the EPA must identify a certain area of commercial endeavor or a certain product as a major noise source It then has the authority to pursue regulatory activity to control and monitor that area or product Early on the railroads airports certain manufacturing operations and a host of other activities were identified as major noise sources in need of regulatory attention The Agency specifically labeled medium and heavy trucks as significant sources of environmental noise and has set up standards for the testing and control of the total vehicle noise emission package These standards known as the Interstate Motor Carrier Noise Emission Standards are contained in Volume 40 Parts 202 and 205 of the Code of Federal Regulations They have been in force since 1975 and apply to all vehicles in over the highway service as well as to newly manufa
56. xternal noise level permitted is 80 dB A SECTION T weELVE Miscellaneous TIRE STORAGE RECOMMENDATIONS For Tires Not Installed on Vehicles 1 Oil Solvents and Grease Mounted or unmounted tires should never be stored on oily floors or otherwise in contact with solvents oil or grease Nor should tires be stored in the same or adjoining rooms with volatile solvents These solids liquids or vapors are readily absorbed in rubber and will damage and weaken it 2 Ozone Mounted and unmounted tires should be stored away from electrical devices such as motors generators arc welders and switches because they are active sources of ozone Ozone attacks rubber causing it to crack perpendicular to any applied stress Such cracking exposes the new rubber surface at the base of the crack to greater stress and consequently to more severe ozone attack until eventually the cracks can penetrate to the carcass where continued rubber degradation could cause carcass failure Minor ozone induced surface cracks will seldom cause tire failure but can form an access route for foreign material to penetrate the carcass once the tire is placed in service 3 Heat and Light Tires should be stored in a cool place away from direct sunlight or strong artificial light Both heat and light are sources of oxidation of the tire surfaces The oxidation is characterized by a crazed or alligatored surface which does not penetrate t
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