In the process of rebuilding an RS rear diff that I picked up and to me it looks very worn...but I'm no expert so was wanting confirmation.





Wear lines in the valleys





Does this look like the bearing has been spinning in the casing?

Is the casing ok to rebuild?





Wear grooves in the valleys and you can see the teeth appear worn on both sides.

 

Case is probably ok. Make sure the bearings are still a tight fit on the ring gear carrier. That gearset has had a rough life, and the wear pattern is going off the heel of the ring. It needs to have the setup adjusted, but the gear set will likely need replaced if you want it be quiet.


What was the backlash before you pulled it apart?

 

Didn't bother measuring backlash as was going to check and re-shim accordingly when reassembling.

I think I'll use another pinion and crown gear that I have which look in better condition than these.

Any tips on getting the diff back into the housing with the shims? Last one I tried to do really didn't want to go back in!


Thanks for the reply.

 

You just kind of have to shove it in. A dead blow hammer helps a lot..

 

Any suggestions on how to work out pinion shim sizes without the Mitsui special tools?

Workshop manual has a formula based on values from 2 special tools i don't have access to.

F = A + B + C - 1/2D - 86.00 mm


There has to be another way!

 

The only way is to set it up, and check the pattern. For this method it is best to use a pinion bearing that has had the ID ever so slightly enlarged so that you can more easily change the shim underneath it as needed.

 

Handy tip!

I shall sand up the inside of an old bearing although i guess that means we assume the new bearing is the exact same size?

Or do you do it to the new bearing?

 

Do it to an old bearing. Make sure it remains round, don't sand out half of it (seems obvious, but it's important).

You will recheck the pattern with a new bearing. The 2 times I've used this method on ford 8.8 rear ends, it's worked like a charm.