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MGB 64 MGB trans problem

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Martin Mieger

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Hello All: I am having a problem with my trans.The clutch is good from the"start in gear" test,but will not go in to gear when running.The real poser is that all works great when I jack the rear wheels off the ground.The car has had the later all syncro trans installed by the prior owner.All worked well for a while then this just showed up one day.Leave it to Murphy.Thank for any help Martin
 
Oh crikey, another curve ball! This one is whispering "clutch" to me. The fact that it behaves properly when there is no load on the transmission is an indication, together with the fact that it doesn't want to know when the wheels are on the ground. A worn clutch would have shown up long before this, so I'm not conviced that it is worn.

When did you last bleed the clutch? If water is in the system (and it does get in there, same as your brakes) it may just need bleeding and replacing with fresh fluid. If that does not work, then you might look at the slave cylinder. Is there a leak? The master cylinder also might be past its "best by" date. I suspect a problem on the hydraulic side rather than a mechanical problem. Any other thoughts?
 
Okay, always try the cheapest solution first. I would suggest bleeding the clutch again. Since they were replaced recently, you may have an air pocket trapped, which is affecting the operation of the clutch. The fluid cannot be compressed but air can, which will cause the clutch to not engage fully. It still sounds like this is the problem to me. Buy fresh brake fluid, and do a thorough bleeding, then try it again. If it still isn't right, then check the actuation of the pushrod from the slave to the clutch itself.
 
Thanks for all the responses.I have rebled the hydrolics and am getting 1/2 inch of solid travel with no creep.Talked thru problem with local MG mechanic.He thinks it is throw out fork or throw out bearing.I do have a question about peoples experience with carbon block vis bearing throw outs.Local mechanic does not like bearing type.Says they have short service life.If I am going to pull this down I would like the new clutch to last.Comments?
 
<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Martin Mieger:
...I do have a question about peoples experience with carbon block vis bearing throw outs.Local mechanic does not like bearing type.Says they have short service life. ...I would like the new clutch to last.Comments?<hr></blockquote>

I tend to lean towards a bearing type but never had to do one a second time so have no clue how long either type lasts. In your shoes, I'd go with his recommendation if he's doing the work.

John C
 
Don't forget to check for wear in clevis pin and clevis hole (in pedal). The link below talks about this....had similar problem in my old Sprite.

https://www.mgb-stuff.org.uk/clutch.htm

Also, since trans was swapped, be sure slave cyinder rod (the rod between the slave cylinder and throwout arm) is correct length. Occasionally, these are shortened or lengthened (by welding) in an incorrect attempt to "adjust" for clutch wear. I've seen this and also read about it in one of those "fix-it" MG books.
 
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