CharlieB Posted May 7, 2007 Share Posted May 7, 2007 Ok this is embarrassing so be gentle with me! I've just rebuilt my gearbox, new synchros, new synchro hub springs & all endfloats etc checked but I still sometimes get a crunch engaging 2nd gear & occasionally 3rd. Could I have got something wrong on the rebuild or is it the clutch?I had the same problem (pre-rebuild) when this gearbox was on the back of the previous engine (different clutch) How do I diagnose the problem, it's very frustrating! Link to comment Share on other sites More sharing options...
Alex Posted May 7, 2007 Share Posted May 7, 2007 Have you tried bleeding the clutch the symptoms sound very similar to those I had when I incorrectly bled the clutch. Might be wrong often am (so the wife says). Alex Link to comment Share on other sites More sharing options...
Deleted User Posted May 7, 2007 Share Posted May 7, 2007 post removed on request of author Link to comment Share on other sites More sharing options...
CharlieB Posted May 7, 2007 Author Share Posted May 7, 2007 Thanks, I'll give it a try. So the suggestion is the clutches are not made correctly? Link to comment Share on other sites More sharing options...
Deleted User Posted May 7, 2007 Share Posted May 7, 2007 post removed on request of author Link to comment Share on other sites More sharing options...
CharlieB Posted May 8, 2007 Author Share Posted May 8, 2007 I looked at my notes on rebuilding the box, 2nd & 3rd had the new synchros whereas 1st & 4th had the best of the old ones. I wonder if this is significant? The 2 new synchros looked ok but could they be faulty?I don't remember 3rd being a problem before & I found the broken spring in the 1st/2nd hub. Link to comment Share on other sites More sharing options...
Mac Posted May 8, 2007 Share Posted May 8, 2007 Clutch inner plate right way round? Link to comment Share on other sites More sharing options...
junkuser Posted May 8, 2007 Share Posted May 8, 2007 Running new cones on old gears could take some time to bed in, assuming they were not lapped. Shimming the synchro hub springs to increase the pressure required to move the hub axially by about 20% overcomes this sort of problem without noticeably increasing the effort required to change gears. Link to comment Share on other sites More sharing options...
CharlieB Posted May 8, 2007 Author Share Posted May 8, 2007 "Running new cones on old gears could take some time to bed in" I'm not convinced of that, I wouldn't accept a new or recon box that crunched the changes for the first few hundred miles."Shimming the synchro hub springs" This sounds like an idea, the only thing I couldn't measure was the force required to move the hubs, maybe the new springs are a bit weak.Oh well, suppose I better take it out again, maybe after SEM. Link to comment Share on other sites More sharing options...
junkuser Posted May 11, 2007 Share Posted May 11, 2007 What I meant to imply was that running new cones on old gears was not a good idea and likely to prove unsatisfactory, could take forever to start gripping, if ever.The specified axial loads probably were satis for all new componentry. In a used box the cones on the gears will have some degree of wear and not have the smooth progressive taper as designed but rather a series of grooves.Overloading the springs is not a purist approach, simply a way to compensate for imperfections. Replacing everything is rather expensive.I figured that the original designers went for the lightest pressure that would reliably work so guessed a 20% increase would be tollerable. May be 10% would have been OK but I didn't want to do the job twice.Increasing approx 20% (difficult to get consistant, repeated, readings) required 2 to 4, 4 thou shims in my case.The balls MUST be replaced as they slide, rather than roll, and must develop flats. These ideas are only put forward in case they are of use to someone if only to improve upon.There will be plenty of critics but it worked for me. Link to comment Share on other sites More sharing options...
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