quick diff questions

[surfer5567]

I have an expo 8.8 that has an open diff. Im wanting to swap out the diff for a tru trac. Besides pulling axles and unbolting diff, will I need to reshim the pinion? All im doing is swapping the ring gear to the new diff and thats it correct? No shims required?

 

[bigmark303]

Ive only done two differential changes, but on each I just scored the ring gear and pinion with a long flathead before removal. Swapped the ring gear over to the new differential and lined up the score marks I made and never had to do anything more.

 

[Explorin94]

More than likely you will not need to reshim the pinion. When you install the tru-trac set it up with the old shims from the stock carrier and new bearings and races. Clean the ring gear good and apply some gear marking compound to about 10 of the ring gear teeth. Then turn the pinion till the painted are reaches the pinion gear. Roll the painted area through the pinion where the gears mesh back and forth a couple times. Check your gear pattern which should about the middle of the ring gear both ways.

 

[4x4junkie]

Definitely won't need to mess with the pinion gear at all, but you'll likely need to reshim for the new TrueTrac carrier.

The way to do this is to check the ring gear backlash with a dial gauge before you pull the original carrier out (check it in 3 or more places around the gear and average it), and then shim the new carrier to the same backlash while maintaining proper preload on the carrier bearings.