Replacing taper bearings complete necessity for a rebuild?

[Toni]

Originally Posted by JackM

That will be a little dangerous. The races float when the case is fully warmed up, so they will possibly come apart or loose in the trans if you cut them. If you heat up the case the races should fall or slide out pretty easy.

Jack

Thanks for the tip. I used a little heat and my puller and they came out pretty easily.

Originally Posted by Devilmightcry

wait. so in our tranny the shims are behind the race and not the bearings?

Yup, behind the races, once the bearings are pressed onto the shafts/diffs etc they stay on.

Originally Posted by phantomrt

The shims are behind the outer bearing race. I'm not sure what is meant when you say "behind the bearings".

I am an overall inexperienced transmission rebuilder, so stick with Jack's advice over mine. I have replaced taper roller bearings in a few of my own manual transmissions over the years. Every time I did it, replacement of the bearing alone resulted in perfect bearing preload by using the exact same shims that were in there before. My theory is that the bearing manufacturing tolerances are so good that the shims are not there for taking up slack in bearing tolerances, but instead all the tolerance is in the cast aluminum transmission case instead. Or maybe tolerances in the transmission shaft also.

On a 2nd note, how in the world did you mess up one of these bearings just by assembling the transmission? They are made of the hardest metal in the world and no chisel that I have in my tool box can do more than barely scratch them. Maybe they're just cheap chisels.

Next time I do this, I am going to try heating up the aluminum housing to remove the outer race--I've always carefully cut the race with my dremel, and at which point it just falls out.

I just replaced all my bearings and I did have to remove the smallest spacer from each of the races to bring them in spec. That dremel technique will only work removing the old races but you will need to be able to remove the new races when properly checking the preload.

-Antoni