RC67GT6 Posted December 14, 2022 Share Posted December 14, 2022 I have been told that its possible to also find reworked lay gears. that would be acceptable as well. Interested if Mike Papworth is still installing hardened steel sleeves that also allow longer rollers to be used. Quote Link to comment Share on other sites More sharing options...
mikeyb Posted December 14, 2022 Share Posted December 14, 2022 6 hours ago, RC67GT6 said: Interested if Mike Papworth is still installing hardened steel sleeves that also allow longer rollers to be used. best to contact him direct I would suggest Quote Link to comment Share on other sites More sharing options...
RC67GT6 Posted December 14, 2022 Author Share Posted December 14, 2022 Thanks for the reply Mikey if I get no direct part replys I will reach out him. I know many of us are busy tinkering. Quote Link to comment Share on other sites More sharing options...
RC67GT6 Posted December 14, 2022 Author Share Posted December 14, 2022 It seems I cant reach out to Mike Papworth on the lay gear until I get at lease 10 qualifying club communications. 😴 Quote Link to comment Share on other sites More sharing options...
thescrapman Posted December 15, 2022 Share Posted December 15, 2022 8 hours ago, RC67GT6 said: It seems I cant reach out to Mike Papworth on the lay gear until I get at lease 10 qualifying club communications. 😴 Just phone him 🙂 Quote Link to comment Share on other sites More sharing options...
JumpingFrog Posted December 15, 2022 Share Posted December 15, 2022 (edited) 12 hours ago, RC67GT6 said: It seems I cant reach out to Mike Papworth on the lay gear until I get at lease 10 qualifying club communications. 😴 I don't think you'll get much advice other than to contact Mike, he's the only one doing such repairs to these gearboxes now. Finding the correct NOS laygear is unlikely, and 6-cylinder gearboxes suffer badly for wear. There is one expensive alternative, NOS UKC8749 is available, as is UKC8748WO (29T 1/2 sleeve) and UKC8750 (17T reverse idler). This is a late TR7 4-speed laygear with the stronger reverse teeth, assuming your GT6 gearbox isn't an early one (small synchros and different helix angle on 2nd?) it should mesh with your existing gears. But I know that when using single-rail parts in a 3-rail gearbox there can be issues with getting reverse to work correctly (two different spacer sleeves exist for reverse idler shaft). Edited December 15, 2022 by JumpingFrog Quote Link to comment Share on other sites More sharing options...
RC67GT6 Posted December 15, 2022 Author Share Posted December 15, 2022 Glad to hear you think Mike is still a prospect. They are KC 103, 104, & 500, SN boxes all 21 tooth so repair or used p/n212993 is the way to go. I wish on finding a NOS. 🤩 Quote Link to comment Share on other sites More sharing options...
RC67GT6 Posted December 15, 2022 Author Share Posted December 15, 2022 I don't have a phone number or email for Mike and cant even message him though the club system! Being a rookie rated member limits my use of this site option. Quote Link to comment Share on other sites More sharing options...
Clive Posted December 15, 2022 Share Posted December 15, 2022 19 minutes ago, RC67GT6 said: I don't have a phone number or email for Mike and cant even message him though the club system! Being a rookie rated member limits my use of this site option. Mike has an advert in some magazines, so here is the number he publishes 07768 775170 Quote Link to comment Share on other sites More sharing options...
mikeyb Posted December 16, 2022 Share Posted December 16, 2022 you must be nearly at the statutory number of posts by now, lol Quote Link to comment Share on other sites More sharing options...
RC67GT6 Posted January 21, 2023 Author Share Posted January 21, 2023 JumpingFrog You mentioned the helix angle under 2nd gear on the GT6 main shaft. Isn't that helix only for 3rd & 4th gear synchro hub? 2nd gear bushing covers it so it does nothing for 2nd gear. By the way does anyone have any experience with BASTUCK main shafts? Thx. Rob Quote Link to comment Share on other sites More sharing options...
JumpingFrog Posted January 22, 2023 Share Posted January 22, 2023 Im not sure what you mean, I was talking about buying a Tr7 4-speed laygear which are still easily available NOS and then changing your existing mainshaft gears to match. AFAIK, 1st and 3rd are always the same, but has at least 3 different types. I think you're referring to the splines on the mainshaft, which as you say are only for the synchro hubs and should be the same. Quote Link to comment Share on other sites More sharing options...
RC67GT6 Posted January 22, 2023 Author Share Posted January 22, 2023 Ah yes sorry for the confusion. I'm still planning to go Mk1 GT6 Gear box and in fact I may have a source for new OD main shafts. But also considering sleeving the tips of some old ones. Bastuck Mainshaft G31SPTMK4 OD shown on the left is close to OEM on right. The only difference being the 3rd gear Circlip width and the 2nd & 3rd Gear bushing journal being a few thousands over the OEM size. I suspect that a Mk4 bushing and Circlip could get it all pulled to gather. Worst case I would need to open the bushing IDs and stack 2 Circlips. Quote Link to comment Share on other sites More sharing options...
JumpingFrog Posted January 23, 2023 Share Posted January 23, 2023 (edited) Others have noted tolerance issues with the Bastuck shafts, there was a thread on the TSSC forum: https://forum.tssc.org.uk/topic/8680-2nd-gear-seized-to-mainshaft/ I would suggest you complain, since the circlip groove is incorrect. If it was only the journals oversized, you could have it ground down. Had a similar issue with a shaft from a well known gearbox specialist. Edited January 23, 2023 by JumpingFrog Quote Link to comment Share on other sites More sharing options...
RC67GT6 Posted November 14, 2023 Author Share Posted November 14, 2023 Found my solution to fixing lay-gear P/N 212993. Are others lay-gears that are worth saving ? Regards, Rob Quote Link to comment Share on other sites More sharing options...
RC67GT6 Posted November 14, 2023 Author Share Posted November 14, 2023 Still looking P/N 212993 cores. Quote Link to comment Share on other sites More sharing options...
GT64fun Posted November 15, 2023 Share Posted November 15, 2023 23 hours ago, RC67GT6 said: Found my solution to fixing lay-gear P/N 212993. Could you describe what you have done there please Rob? Dimensions, materials etc. and by whom. Could be useful to others. Ian Quote Link to comment Share on other sites More sharing options...
Tim Bancroft Posted November 15, 2023 Share Posted November 15, 2023 I had a good chat with Mike Papworth at the NEC on Sunday. He is actively looking at having parts remade and can still do overdrive conversion kits/sets. Sorry to hijack this thread. Quote Link to comment Share on other sites More sharing options...
RC67GT6 Posted November 16, 2023 Author Share Posted November 16, 2023 Hi Ian As you requested. The bushings are 52100 material with a hardness of 62/64Rc. verses the OEM 48/52Rc. They are custom ground here in the USA and have a wall thickness of .036" with an ID of .8438" This allows for the use of standard spec needle bearings and lay shafts. The newly ground bearing bore is sized for a light bushing press fit with Loctite #648. Since most machine shops wont touch automotive gear parts it was done by me for my MK1 GT6 transmissions and because of the poor consistency on gear OD run out its wasn't hard to improve the over all gear during the re-boring process. This was a year long development project for me and I had more bushings made than I needed so extra laygears repairs are in the future to help pay for the extra tooling purchaesed for my lathe. Regards, Rob Quote Link to comment Share on other sites More sharing options...
.thumb.jpeg.b15b81ef10abeea1c3039ae03c4a9f3a.jpeg)
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.