Anthony Posted January 6, 2013 Share Posted January 6, 2013 I've taken my gearbox apart for rebuilding, and need to check things out before rebuilding itSince this is the first gearbox I've rebuilt, and I have no idea what I'm looking for I'm hoping someone can tell me what I should look out for?ie: What are and aren't acceptable levels of wear, etc....Now, on with the pictures.......This is the end of the mainshaft, it looks as those the hardening has worn through to me (but I don't know what I'm talking about so I could be wrong)Here you can see a small chip out of the first gearThis pictures shows some wear on the teeth, I've pointed out the worst one, but you might be able to see the others have wear tooAnother chip, this one is on the reverse/selector hubAnother picture of first gearAnd some general/overall picturesSo, what does everyone think?Do I need a new first gear and selector hubs?Is my mainshaft scrap?I was planning on replacing the baulk rings and circlip on third gear, but I've heard the new ones are awfulWhat should I do about the input shaft?Any other thoughts? Quote Link to comment Share on other sites More sharing options...
Mark Hammond Posted January 6, 2013 Share Posted January 6, 2013 Most of that, if not all will polish out..... ;DM. Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted January 6, 2013 Share Posted January 6, 2013 Mainshaft spigot is shot (though I have seen FAR worse!) - that's the worst news. 1st gear probably ok for a road car with std engine. Selector dog teeth are bit borderline.What is the lay shaft like? And the inside surface of the laygear cluster under the needle rollers? Hardened surface under those is often damaged....... That is bad news too.NickPS. not the same gearbox but similar - you may find this interestinghttp://www.buckeyetriumphs.org/technical/Gearbox/GearboxOverhaul1/GearboxOverhaul1.htm Quote Link to comment Share on other sites More sharing options...
Mark Hammond Posted January 6, 2013 Share Posted January 6, 2013 Mick Dolphin best odds for NOS parts if you're very lucky.M. Quote Link to comment Share on other sites More sharing options...
Anthony Posted January 6, 2013 Author Share Posted January 6, 2013 1218 wrote:Most of that, if not all will polish out..... ;DM.Good to hearI'll get it looking better than new in no time 8)(whilst I was waiting for some replies I was actually cleaning my diff......with a toothbrush :B ) Quote Link to comment Share on other sites More sharing options...
Anthony Posted January 6, 2013 Author Share Posted January 6, 2013 Nick_Jones wrote:Mainshaft spigot is shot.............Thanks NickAs requested, here are some further pictures for youFirst picture shows Layshaft clusterHere, you can make out the contact patch on the first gearThere is also a chip on the gear I have highlighted, and also the gear two steps nearer to the cameraWear patch on second gearChips on second gearCouple of chips on third gearFront of layshaftThere's a small line where the needle rollers locate, but it doesn't seem to be worn into the surfaceRear of layshaft Quote Link to comment Share on other sites More sharing options...
JensH Posted January 6, 2013 Share Posted January 6, 2013 Looks like your layshaft had a new bush once?NOS or better s/h ones on ebay? Quote Link to comment Share on other sites More sharing options...
Richard B Posted January 7, 2013 Share Posted January 7, 2013 Is that an O/D gearbox?Canleys sell an uprated mainshaft for the D'type GT6 box with a larger tip. This uses the TR7, Dolomite 1850 roller bearing. You have to have the input shaft machined and hardened to suite.I had this on my GT6 box, until I twisted the rear splines on the mainshaft :B Quote Link to comment Share on other sites More sharing options...
Anthony Posted January 7, 2013 Author Share Posted January 7, 2013 Yep, gearbox is D-type overdriveHow exactly are the Canley's shafts updated?My limited knowledge makes me think the following.....The standard mainshaft would either has its tip cut off and a larger one welded in place, or the old tip is built-up (welded) with a hard surfacing rod and then machined to sizeDoes any of that sound right?The standard input shaft bore is then machined to accept the larger tip and bearing?Also - if I go for a j-type overdrive is anything different needed besides the adaptor plate? Quote Link to comment Share on other sites More sharing options...
Richard B Posted January 7, 2013 Share Posted January 7, 2013 New mainshaft from Canleys AFAIK made with a larger tip, yes input shaft machined and hardened to take the Dolomite 1850 roller bearing.You can get a J Type mainshaft and adapter from CC or Mike Papworth, I think you need the 1850 internals to go into the GT6 casing. This gives you the three rail selector, but the J'Type goodies.I'v just had one of these created for me. 8)You can have the mainshaft tip sleeved, but don't expect it to last, new mainshafts are about £65 last time I looked. Quote Link to comment Share on other sites More sharing options...
Anthony Posted January 7, 2013 Author Share Posted January 7, 2013 Good stuffCanley's and Mike P. are both pretty close to meWhat kind of price does the j-type rebuilt gearbox usually cost?(I've been seeing mainshaft prices from £100 to over £200) Quote Link to comment Share on other sites More sharing options...
thescrapman Posted January 7, 2013 Share Posted January 7, 2013 Another option is to get machining work done to fit a full sleeved bearing to teh end of the mainshaft. It involves about 10thou off the end, and teh sleeve press fitted on, then the imput shaft openning out to take the outer race, and the bearing sitting in between.I have had 1 done, seems fine so far. The only problem with the box was the bearing had failed big time, rest was really good.There was an article in teh TSSC mag many many years ago about it.The chips on reverse are fine.Swap the synchro rings about to get best one on 3rd or is it first, which ever is worn, swap with the other one. Someone will say the best thing to do.CheersColin Quote Link to comment Share on other sites More sharing options...
Anthony Posted January 7, 2013 Author Share Posted January 7, 2013 Some pictures of the Layshaft..............Scrap?? Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted January 7, 2013 Share Posted January 7, 2013 Layshaft doesn't look too bad........ Colour change on the areas where the bearings run is ok. A step at the edges is not and neither is any pitting in those areas.The large-tip mainshaft in D-type or J-type form is worthwhile - it's a fair bit stronger. They will be expensive as they are new items and different from factory versions. Note that the input shaft also has to be modified to house the larger bearing. Colins repair suggestion can also work well but might not last so well with a 2.5.......As Colin says you may get away with swapping the synchros around. The least worn are usually 1st and 4th and worst usually second followed by 3rd. Beware of the new synchros available - most are christmas-cracker quality.Might be worth taking the bits to Mike Papworth or Dave P for an opinion. Most of the rebuild cost is the parts - it doesn't take long to put a box together when you've as much practice as they have!CheersNick Quote Link to comment Share on other sites More sharing options...
TR7th Heaven Posted January 7, 2013 Share Posted January 7, 2013 1903 wrote:Good stuffCanley's and Mike P. are both pretty close to meSorry, but Mike Papworth reconditioned my Vitesse box at a cost of £460 and it's as noisy as hell less than a year and only 1200 miles later. AvoidRich :( Quote Link to comment Share on other sites More sharing options...
Gt6s Posted January 7, 2013 Share Posted January 7, 2013 Convert to big T box, fit and forget.Laurence Quote Link to comment Share on other sites More sharing options...
Anthony Posted January 7, 2013 Author Share Posted January 7, 2013 TR7th_Heaven wrote: Sorry, but Mike Papworth reconditioned my Vitesse box at a cost of £460 and it's as noisy as hell less than a year and only 1200 miles later. AvoidRich :(Thanks I can accept that things can go wrong from time to time.....But the real test is how people/businesses react (or don't) when things do go wrong Quote Link to comment Share on other sites More sharing options...
Anthony Posted January 7, 2013 Author Share Posted January 7, 2013 Gt6s wrote:Convert to big T box, fit and forget.LaurenceYou are a very bad person ;D Quote Link to comment Share on other sites More sharing options...
mikeyb Posted January 7, 2013 Share Posted January 7, 2013 1903 wrote:Thanks I can accept that things can go wrong from time to time.....But the real test is how people/businesses react (or don't) when things do go wrongsurprised - first bad feedback I have ever heard about Mike & his work? . . . . . . . . . . :-/ Quote Link to comment Share on other sites More sharing options...
Richard B Posted January 7, 2013 Share Posted January 7, 2013 Ditto Quote Link to comment Share on other sites More sharing options...
TR7th Heaven Posted January 7, 2013 Share Posted January 7, 2013 MikeyB wrote:surprised - first bad feedback I have ever heard about Mike & his work? . . . . . . . . . . :-/Yes MikeyB, that's why I went to him. His reputation was good and Canley Classics recommended him as well. I'm hugely disappointed because the gearbox is so bad it ruins the car, it really does. I could almost cry. I paid a lot for the recon (£460) and whilst I didn't expect a totally silent gearbox I expected it to be better than the old one was. It's very noisy in the first 3 gears, there's also a high pitch squeeling at over 55mph and a vibration at over 45mph which I can only guess is the gearbox as well. Gutted.I've no wish to tarnish anyone's reputation but I don't want anyone to waste their money like I have.Rich :( Quote Link to comment Share on other sites More sharing options...
Mark Hammond Posted January 7, 2013 Share Posted January 7, 2013 Richard_B wrote:DittoLikewise..M. Quote Link to comment Share on other sites More sharing options...
Anthony Posted January 8, 2013 Author Share Posted January 8, 2013 QuestionIf the gears in my spare gearbox are in better condition than these ones, can I mix and match them to make a nice set of gears?I didn't know if this would be ok or if the gears would be worn to a different shape, which could cause additional wear and noise?Good idea? Bad idea? Quote Link to comment Share on other sites More sharing options...
Dannyb Posted January 8, 2013 Share Posted January 8, 2013 Bad idea. Not that I have rebuilt a gearbox. But I thing the principle is the same when changing sprockets and chains. Always use new sprockets with new chains. Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted January 8, 2013 Share Posted January 8, 2013 1903 wrote:QuestionIf the gears in my spare gearbox are in better condition than these ones, can I mix and match them to make a nice set of gears?I didn't know if this would be ok or if the gears would be worn to a different shape, which could cause additional wear and noise?Good idea? Bad idea?Best to swap as a whole set. Provided both gearboxes have the same basic gear cut (and there are some different ones - two different helix angles used on 2nd gear over the years IIRC) then you can mix and match in theory, but could end up noisy due to different wear patterns as you say......Nick Quote Link to comment Share on other sites More sharing options...
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