Supplemental Information & Instructions
Contents
1. CO oOo N O oO A W N M Product Information 128 225 3H2865 Instructions Drafts 128 225 3H2865 461 868 3H2865K_INST docx Created on 11 February by Michael Grant Revised by Michael Grant Mick Pratt amp Davis Aidnik on 11 March 2014 Supplemental Information amp Instructions for 128 225 or 3H2865 Bearing Assembly 20 Needle Roller and or 461 868 or 3H2865K Layshaft Bearing Kit w Spacer Tube MGA all MGB w standard gearbox to engine number GB74719 The 461 868 or 3H2865K Layshaft Bearing Kit 1a Each bearing assembly comes in the original box 1b Each bearing assembly is wrapped in protective paper 1c Once unwrapped the assembly inside the outer shell is visible 1d The special retaining washers with the lip or flange on the inner edge 1e Some but not all bearing assemblies come with one snap ring 1f The 20 needle bearings Note the pins on each end these are trapped under the lip or flange of the retaining washers 11d 1g We include 4 snap rings with each kit any that you get with a bearing assembly will be extra 1h The spacer tube which we make on the Moss Machine Shop We suggest you leave the bearing assembly 1c alone until you have read the rest of this the bearing assembly is a lot easier to deal with as a unit than as 20 separate bits About this Kit The 461 868 or 3H2865K Layshaft Bearing Kit represents a return to the original design specification for the layshaft bearings for2. the three synchro gearbox fitted to the MGA and early MGB By reintroducing the original bearings and dropping the caged bearings sold for this application Moss Motors has eliminated what many have blamed for the excessive wear of the layshaft the caged roller bearings that cut the number of load bearing rollers in half This kit is intended for stock engines in a street application where your laygear does not need replacing If you need a laygear or if you have a modified engine and or a more spirited driving style we suggest our Uprated Laygear kit 461 571 or 22H54k Developed by Moss Europe this is another Moss exclusive Built around the stock layshaft it comes with a new laygear fitted with uncaged needle roller bearings that are longer than stock effectively doubling the load bearing area over the original MG design It is the most durable package we offer for the early layshaft laygear Please see our website www mossmotors com for more information on these options For pretty much everything but the fire breathing race car Moss has a solution And everyone wants to know where we found them Suffice it to say we discovered a substantial quantity in a warehouse in England and we bought them all The bearings are from two manufacturers The yellow boxed bearings shown above are from RHP and the blue boxed bearings not shown are from R amp M These bearings have not been manufactured for many years For us this is the ultimate barn
3. 868 3H2865K_INST docx Created on 11 February by Michael Grant Revised by Michael Grant Mick Pratt amp Davis Aidnik on 11 March 2014 How it All Goes Together 4 gear end or Big End of Laygear ITY 4 9 1st gear end or m OY Small End of Laygear N yg Europe 7abc 128 225 26 190 _ 11G3027 61 580 11G3026 Tube layshaft bearing spacer The following items are not included thay are illustrated amp listed here for clarity 461 610 G3578_ Thrust washer rear 0 157 461 620 G3579 Thrust washer rear 0 158 7m 461 560 H3305 Layshaft 0 645 nominal diameter 7n 1461 570 22H54 Laygear for 1H3305 layshaft f you need a laygear consider the 461 571 Laygear kit 461 630 1G3580_ Thrust washer rear 0 163 i Page 4 of 6 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 221 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 M Product Information 128 225 3H2865 Instructions Drafts 128 225 3H2865 461 868 3H2865K_INST docx Created on 11 February by Michael Grant Revised by Michael Grant Mick Pratt amp Davis Aidnik on 11 March 2014 asara tion Tips refer to Fig 7 12 13 15 Using the layshaft as a guide slide the open end of the bearing assembly About Snap Rings Four snap rings are needed Some of the bearing assemb
4. arney Gaylord s website mgaguru com has a good section on disassembly and inspection of the gearbox Both will tell you to carefully check the gears and we ll say pay particular attention to the inside of the laygear where the needle roller bearings ride If the surface inside the laygear is worn renewing the bearings will be a bad investment you need a new laygear Why Not Just Tell People to Follow the Factory Workshop Manual Section F 5 June 1956 revision at right from the MGA Service Manual has been inserted here for Section F 5 eee THE LAYSHAFT GEAR We found it to be not entirely helpful First and The assembly sequence of the layshaft bearings is as foremost neither the MGA or MGB workshop follows a circlip at the rear a needle race a single long manuals address the pre assembled bearing Most distance tube a circlip a needle race a circlip a needle likely they were not available until well after the race a circlip two races being fitted at the front end manuals were written and one at the rear l When assembling fit a circlip to the innermost groove However if you have never had your gearbox apart the gear pushing it in from the front or large gear before we felt there was too much left to be end Shes l discovered the hard way Given the frustration and Hold the layshaft vertically in the vice stepped end aggravation inherent in a trial amp error process and downwards the potential for an expens
5. aylord mgaguru com the R amp D Team at Moss Europe particularly Michael Pratt and David Aidnik Product Development Engineer at Moss Motors Ltd Notes Any suggestions that you may have that will improve the information especially detailed installation notes are welcome Please use the simple email form on the Contact Us page on the Moss website http www mossmotors com AboutMoss ContactUs aspxIf you prefer you may call our Technical Services Department at 805 681 3411 So many people call us for help that we are often not able to answer the calls as fast as we d like and you may be asked to leave a message We respond to every call for help as quickly as we can which is normally within 2 business days but when the volume of calls and emails is high it may take longer We apologize in advance for the inconvenience Moss Motors Ltd 440 Rutherford Street Goleta California 93117 In the US amp Canada Toll Free 800 667 7872 FAX 805 692 2510 805 681 3400 Moss Europe Ltd Hampton Farm Industrial Estate Hampton Road West Hanworth Middlesex TW13 6DB In the UK 020 8867 2020 FAX 020 8867 2030 Instruction Sheet 128 225 3H2865 461 868 3H2865K March 2014
6. cond bearing 7a Page 5 of 6 252 253 254 255 256 25 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 M Product Information 128 225 3H2865 Instructions Drafts 128 225 3H2865 461 868 3H2865K_INST docx Created on 11 February by Michael Grant Revised by Michael Grant Mick Pratt amp Davis Aidnik on 11 March 2014 16 To install bearing 7a on the 4 gear or front end you will be repeating steps 5 12 17 As soon as the snap ring if included in the 7a bearing assembly clears the end of the outer shell stop 18 You may use the snap ring from the assembly or if you wish you can replace it with one of the four 326 190 11G3027 snap rings supplied in the kit Insert the snap ring in the outer snap ring groove This completes the installation of the two bearings and the three snap rings in the 4 gear or front end of the laygear 19 Moving to the 1 gear end of the laygear we have only a spacer tube 7h one bearing 7c and the outer snap ring 7i to deal with and they are fitted in that order 20 Insert the spacer tube 7j into the 1 gear end of the laygear and press it home It will stop when it comes up against the inner most of the three snap rings 7h installed from the 4 gear end 21 Install the 3 bearing assembly 7c using steps 4 11 above as a g
7. d into the laygear Using the small end of the tubular drift described above start pushing the bearing out of the shell and into the laygear As soon as the snap ring in the bearing assembly clears the end of the outer shell stop The reason for Stopping is that this 2 snap ring 7g must be pushed over the outer snap ring groove If you simply push it in straight it will pop into the outer groove and you will have fun trying to get it out Remove the tubular drift and extract the snap ring and set it aside Use the full sized end of the tubular drift to push the bearing with the two retaining washers into the layshaft until the inner retaining washer comes up against the first snap ring 7h you installed Remove the layshaft carefully from the laygear while you press on the tubular drift holding the bearing assembly in position as you withdraw the layshaft Now remove the drift Once the bearing assembly is seated the two special retaining washers overlap the pins on the ends of the needle bearings making it impossible for the needles to fall out when the layshaft is removed In reality the grease on the bearings and on the layshatt would hold the needles in place without the special washers Install the 7g snap ring and push it over the outer snap ring groove following the procedure used in steps 3 4 5 above Once the 7g snap ring is in the proper groove the inner bearing is secured and you can _ proceed to install the outer or se
8. d the noise decreases going to 3 and it goes away after shifting to 4 the layshaft layshaft bearings are the probable cause And another good rule of thumb when it is time to change out the clutch it is time to check the layshaft and the inside of the laygear for wear If you detect layshaft layshaft bearing noise plan on dealing with it soon It will not be long before more serious problems like broken gear teeth develop You can avoid all that by taking action quickly It is much easier and much less expensive to replace the layshaft and bearings by themselves without adding a gear or two to the bill Page 2 of 6 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 M Product Information 128 225 3H2865 Instructions Drafts 128 225 3H2865 461 868 3H2865K_INST docx Created on 11 February by Michael Grant Revised by Michael Grant Mick Pratt amp Davis Aidnik on 11 March 2014 Before you install anything Make sure you have a transmission with the 0 645 diameter layshaft and that it can be rebuilt Nobody should go to the trouble of pulling a gearbox apart without a complete inspection Plan on replacing all worn components usually synchros bearings gaskets and seals The factory workshop manual is essential and B
9. ear end has two The three layshafts in Figure 4 show a progression from almost no wear 4a to very severe wear 4c There is a great deal of discussion on the web about this problem and there are several causes mentioned one being the reduced load bearing surface available related to the number of needles in the caged bearing assembly How can l tell if my layshaft is going Anyone can tell if you need a new layshaft with the old one in hand John Esposito Quantum Mechanics British Gearbox specialist explains how you can get a pretty good idea about the condition of the layshaft and layshaft bearings just by listening to the 3 synchro gearbox 4 gear is your bench mark It is direct drive the laygear is not loaded or involved so 4th is very quiet In 3 gear the laygear is engaged If the layshaft and layshaft bearings are fine it should not be any noisier than 4 gear If there is any increase in noise when moving from 4 to 3 the layshaft is suspect Same thing applies to on gear the laygear is engaged If there is any increase in noise when moving from 3 to 2 the layshaft layshaft bearing problems are confirmed 1 gear is going to be ignored because it uses straight cut gears which are inherently noisy That noise will mask any layshaft related noise that might be there The layshaft layshaft bearing related noise you can hear when down shifting can also be heard when up shifting If 2 gear is noisy an
10. find Page 1 of 6 M Product Information 128 225 3H2865 Instructions Drafts 128 225 3H2865 461 868 3H2865K_INST docx Created on 11 February by Michael Grant Revised by Michael Grant Mick Pratt amp Davis Aidnik on 11 March 2014 A Little History The MGA and early MGB three synchro gearbox share a layshaft that is 0 645 in diameter which is smaller than the later shafts Initially three 3H2865 layshaft bearings were used each being made up of 20 loose needle roller bearings 2b that had pins on each end These pins were trapped under the lip of the special washers 2a supplied as part of the bearing assembly Two of the three bearing sets were fitted on the 4 gear end of the layshaft toward the front leaving a single bearing set for the 1 gear end toward the rear As supplies of the 3H2865 loose needle bearing assembly dried up it was replaced by AAU3052 a caged needle roller bearing assembly 3a While the caged assembly greatly simplified the assembly procedure each one only has 11 or 12 needles depending on the manufacturer compared to the 20 in the original bearings In time the caged bearings became associated with premature layshaft wear The wear is always most severe at the first gear end of the layshaft toward the rear because it is more heavily loaded than the 4 gear end toward the front It certainly does not help that the first gear end is supported by a single bearing assembly while the 4 g
11. ing up in the bore by running a second socket in from the other end When the sockets are pressed together the snap ring will square up in the laygear bore The next Step will be to install the 7b set of needle bearings in the laygear and press it against the 7h snap ring you just fitted Pick one of the three bearing assemblies Liberally apply grease to the bearing whilst still in its outer shell This provides sticktion and will help in keeping the bearing together Make sure all the rollers inside the outer shell are running parallel to the long axis of the assembly and not at an angle Locate the three bent over sections of the lip shown in Fig 11 These hold the bearing assembly inside the shell Using a pair of long needle nose pliers straighten out the bent sections completely The outer shell material is quite thin and it is easily straightened Make sure the lip of the outer shell will not interfere with the bearing assembly when it is pushed out of the shell This is now the open end of the bearing assembly Have laygear lying flat on the workbench not on its end Insert the layshaft into the laygear from the 4 gear big or front end including the outer shell onto the layshaft Slide the bearing assembly up the shaft until the outer shell touches the laygear The outer shell of the bearing assembly will not fit inside the laygear it stays outside The next step is to push the bearing assembly out of the shell an
12. ive mistake or two Smear the shaft with grease and assemble a roller providing instructions seemed to be essential bearing on the shaft against the vice jaws and then slide the gear cluster over the shaft and the bearing with the We hope to develop these instructions further using large gear downwards your tips and suggestions So please if you have Remove the shaft from the vice and push the bearing come up with a better way let us know so we can into the gear against the circlip Fit a retaining circlip share and follow with the end roller bearing assembly and retaining circlip Slide the distance tube into the other end of the gear followed by the other end bearing and circlip Withdraw the shaft from the gear M G MGA Issue 2 2436 6 56 Before we start take a closer look at the bearing assembly 6a The thin outer shell used to hold the assembly together until it is installed 6b One of three folded over edges holding the bearing in 6c The rolled over lip at the front securing the bearing 6d One of 2 special retaining washers holding the needles in place 6e The thin snap ring supplied in some bearing assemblies 6f The needle bearings Page 3 of 6 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 M Product Information 128 225 3H2865 Instructions Drafts 128 225 3H2865 461
13. lies come with a snap ring but some don t so we include four snap rings in the kit If you end up with an extra snap ring great they are handy in case one popped into the wrong groove removing them usually damages them enough to make them unusable The first snap ring to install is 7h Shine a light down inside the laygear from the 4 gear big end you can see 3 snap ring grooves clearly The groove for the 7h snap ring is the 3 groove 1 deep inside the laygear and therefore hardest to fit Hold the snap ring 7h it so that it Is 90 to the long axis of the laygear Fig 9 and insert it in the opening at the 4 gear end aka the big or front end of the laygear using a pair of long needle nose pliers Using the same pliers push the snap ring straight in until it is past both of the outer snap ring grooves Once safely past the 2 outer grooves rotate the 7h snap ring back 90 so that it is in full contact with the bore of the laygear Push the snap ring into the internal snap ring groove with a suitably sized brass drift brass tube or a Craftsman 5 8 socket 0 862 OD on a long extension as shown in Fig 9 Note that the snap ring is not very wide if the nose of the socket is rounded it may not work very well In that case flip the socket around and use the back to push the snap ring The back of the socket is usually unaffected by wear and should make good contact with the snap ring You can square the snap r
14. uide 22 You may use the snap ring from the assembly if there was one or if you wish you can replace it with one of the four 326 190 11G3027 supplied in the kit Insert the snap ring 7i in the outer snap ring groove This completes the installation of the spacer tube bearing and the snap ring in the 1st gear or back end of the laygear Some Final Questions and one last Tip The most obvious question is this How long can expect this bearing set to last The answer is going to depend on the state of tune of the engine and how you drive but remember that this is the original three bearing configuration the factory used in the MGA early MGB gearbox and it has much greater load bearing capacity than the caged needle bearings fitted as replacements for many years Properly maintained you can expect 50 to 75 000 miles with a stock MGA engine driven normally on the street Almost forgot the most important tip of all how do you remove the 2 old snap rings that are down inside the laygear The outer snap rings can be levered out fairly easily The two snap rings the trap the inner bearing must be bashed with a brass drift and a hammer until the snap ring is either bent out of shape or actually broken Honest we asked a lot of folks that rebuild these for a living Be careful not to damage the bearing surface which is why we specify a brass drift Special thanks to John Esposito of Quantum Mechanics john quantumechanics com Barney G
Download Pdf Manuals
Related Search