Jumps out of third

[Woodyalan]

Hi there
My 1098 gearbox was noisy so I stripped it and replaced the bearings. That seems to have quietened it but now it jumps out of third gear (goes in OK but soon jumps out) which it didn't do before. All other gears are fine. Can someone tell me whats the most likely reason, its obviously something I've done or omitted to do.
http://www.mmoc.org.uk/posting.php?mode=post&f=4#Thanks
Alan

[bmcecosse]

Does it jump out on over run - or when under power? Did you renew any of the syncro rings - or gears ? Most likely is that a locking ball/spring have been missed in the rebuild - if everything is otherwise in good order, and there is no excessive endplay on the mainshaft ?

[Woodyalan]

I didn't renew any synchro rings or gears as I could see nothing wrong with them and my aim was just noise reduction. It jumps out under power shortly after engaging third. Feels like it wouldn't happen if you held it in third. The ball/spring theory seems likely, I'll try again, hopefully I won't have to take it all apart again.
Thanks
Alan

[bmcecosse]

Under power = not good... I suspect end float...

[katy]

I stripped it and replaced the bearings.

Did you use the spacer(s) on the rear bearing, to make up the difference between the original and the new bearing?

[Woodyalan]

No, I didn't realize that's what they were for. Would it make that much difference?

[bmcecosse]

Fraid so..... Excessive end float and therefore not fully engaging the dog teeth.....

[katy]

Read all about it on this thread: http://www.mmoc.org.uk/viewtopic.php?f=4&t=50954