Chevy Astro and GMC Safari Forum banner

Rear end rebuild 1996 7.625

2K views 8 replies 4 participants last post by  Astrolife 
#1 ·
Hi all this is my first post, I wanted to document my trials here to share information. I swapped the axle on this thing with junkyard axles 3 times, all were no good. I ordered parts from O'reilly and hadbad luck with parts from them. I ended up rebuilding with a richmond excel ring and pinion, and motive gear bearing set from National Drivetrain. I went from a 3.42 to a 3.73. I used my buddy's shop press, a straight edge, calipers, vise, and various other common tools, and a Bauer electric impact for the yoke nut.
 

Attachments

See less See more
7
#4 ·
Brandon,
I think you will like the 3.73's.
I have that ratio in my '98 AWD, and I just ordered a Torsen rear diff for it.
I did a couple of GM style diffs (Opel race cars) many many years ago, but I have forgotten how much time I spent on them...and we were not worried about diff noise in a race car.
How much time do you think you spent on this regear?
thanks,
Rod
 
#5 ·
Rod,
Hi yes I have spent countless hours, but honestly mainly because it is my first time getting into a diff and I spent most of that time researching and troubleshooting, ordering parts that were not correct from places that did not have knowledge about the specs.

Actual work, maybe 10 hours. Once I knew what I was doing, I would say I spent about 4 hours on the pinion depth setting, then another 2 or 3 putting it all back together.

Other than that, this will be my fifth time swapping this axle since October so it's hard to tell exactly how much time I have spent LOL! :rolling:
 
#7 ·
I have some slop at the yoke, but checked the backlash and that's still good. It seems to be the spider gears, maybe even the internal bore the .middle pin fits into. There seems to be some slop in the floating gears and side gears. The wheel spins maybe a half inch before engaging with the differential while up on stands turning by hand. The thrust washers are pretty well worn also.

My question is: What is the tolerance for movement of the spider gears? Should I just get new ones anyway?
 
#8 ·
Slop at the yoke is a relative thing. With very little pressure,you will feel the backlash of the ring and pinion, high pressure you will feel all the slop in the diff. different depending on how you are judging it.I am mystified as to why you needed to go through all the trouble of lead paint,paint or whatever you used.Being a retired GM mechanic, you have been able to use a new ring and pinion easily, for years.You could just use the shims off the pinion, swap them to the new pinion, then the only thing you need to measure and change is the side shims on the ring gear.has been that way for 30 years, and even the aftermarket adopted it, because it was made so simple.AS far as the slop in the diff, will get back to you later, perhaps you will figure it out.
 
#9 ·
MechBob said:
Slop at the yoke is a relative thing. With very little pressure,you will feel the backlash of the ring and pinion, high pressure you will feel all the slop in the diff. different depending on how you are judging it.I am mystified as to why you needed to go through all the trouble of lead paint,paint or whatever you used.Being a retired GM mechanic, you have been able to use a new ring and pinion easily, for years.You could just use the shims off the pinion, swap them to the new pinion, then the only thing you need to measure and change is the side shims on the ring gear.has been that way for 30 years, and even the aftermarket adopted it, because it was made so simple.AS far as the slop in the diff, will get back to you later, perhaps you will figure it out.
I have heard that is the case with putting new gears in of the same size, but if you switch ratios, you have to reset pinion depth based on the wear pattern using this gear marking compound. It came with the gear set even. The stock shim set the pinion too deep, so did start from scratch. I was getting a pretty strong toe-heel pattern like this:
 

Attachments

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top