Post Reply
Rookie Poster
Posts: 45
Joined: Sun Apr 12, 2009 2:17 am


Post by 67drake » Wed Apr 27, 2011 3:17 pm

I'm setting up an 8.5. Backlash is varying between .002-.005" and I am showing about .002" runout on the ring gear. I know what your going to say-but I filed smooth/deburred and cleaned the ring gear and carrier throughly. What do you do if you run into this? I figure I can clock the ring gear in a different position on the carrier. Any other ideas?
Another thing is that I chased all the threads of the ring gear,and I can easily thread all bolts in by hand till they bottom out. BUT when mounting the gear to the carrier I can only get 1 or 2 in easily,the rest I can only get in a turn or 2,then I have to turn in with a socket. IOW,it almost seems as if the holes on the carrier are just slightly out of alignment with the gear holes. Is this common? Can I open up the carrier holes slightly? If so how?

User avatar
Average Poster
Posts: 849
Joined: Tue Nov 13, 2007 7:56 pm

Re: runout

Post by monzaz » Fri Apr 29, 2011 7:20 am

NO modifying the carrier... It all should be good. Ring might be cocked some if you are on install mode. You want everything with tight tolerances.

WHAT rear are we working on that you chased the ring bolt holes? Nothing with a reverse thread I would assume. Jim

If you have run out there could be some from the ring gear...That is normal BUT most likely your getting it from the carrier preload not being tight enough. EVEN upon set-up you must be sure the carrier is tight in the case. (IF YOU CAN PULL THE CARRIER IN AND OUT BY HAND TUG THE CARRIER PRELOAD IS NOT TIGHT ENOUGH) ad more shim to each side .001 .002 what ever you can fit.
CArrier shim will take some tapping to install....(NOT POUNDING ...IF YOU HAVE TO REALLY SMACK THE SHIM TO INSTALL IT IS PROBABLY TOO TIGHT.) This is one of the areas where experience is KING. The more you do it the more it will become second nature to figure how to use shims to your advantage on working preload and backlash of the carrier and ring and pinion.

IF by chance the run out is still past .005 and your pattern SHOWS that the gears is running out (pattern will shift all over and not be consistent) then I guess you may have a defective ring and pinion... Does not happen that often...BUT DOES HAPPEN.

J D Race

Post Reply