We are rebuilding a rear diff and we are in need of help desperately. We tried everything for 3 day´s now and we can´t get the diff aligned right.
After installing the ring and pinion gear and shimming the diff in the housing there is no adequate tooth pattern.


Look at the pic.



It seams that the pinion gears needs sit deeper in the housing. We installed it with shims in several sizes and without shims. There is no way to aligned it right. We are able to get the correct backlash!
The diff is a series 3.

Any help welcome.

Old parts taken off with part #:

Ring gear: GM 260 508 90 12:41
Pinion: 12:41 GM
Diff Brand: Torson 9022 022 00 113
axle housing cast #: 4000 66 55 SHF2 1293. There is no tag on the housing


New parts installed:

http://www.summitracing.com/parts/ETN-19599-010/

http://www.summitracing.com/parts/RMG-4900451/

New bearings

Camaro SS Year 2002 LS1 T56
Car RPO:
GU6 AXLE,REAR,3.42 RATIO 3.42R(GU6)


Is there any chance that the rear axle housing is a 2 series and not a 3 series. We ordered the parts based on the info that the gear ratio is 3.42 and it won´t fit in a 2 series carrier.

 

Is the pattern pic you posted with or without shims? You are correct that the pinion needs to be deeper in the housing. If this pic is WITH shims, you simply need a thinner shim package in there. If the pic is WITHOUT shims, you have a problem.

 

The pic is WITHOUT shims!!!

 

Wow, I see your dilemma. The difference between the 2- and 3-series carriers has to do with the mating surface of the ring gear. 2-series ring gears are thicker. This shouldn't have any effect on your pinion depth troubles. I checked the part #s listed for the Summit-bought stuff, and I don't see any issues there. Did you happen to verify the part numbers you recieved match what you ordered? I only mention this because I have gotten incorrect parts from Summit on multiple occasions. Your issue appears to be either the pinion area of the housing or the pinion itself. Hopefully someone will chime in with a fresh perspective, as I'm at a loss.

 

If you are 100% sure the pinion bearing is fully seated and the pinion nut is torqued down to spec, you have definatly have a disaster.

 

I'd have to agree- inspect pinion bearings for possible damage, make sure the preload is correct. Sometimes the large pinion bearing can not seat all the way unless you're using a press to install it; it can take quite a bit of pressure w/ new parts.

 

If you can't get it but still want to try, then here's a few tips:
Take it all apart and check the races for junk under the race keeping it from seating and fix that if necessary
Take a flat stone and stone the back of the ring gear to get rid of high spots (usually where the holes are) then reinstall it pulling it on the carrier evenly
Install the pinion and original pinion shim that was in there when you took it apart
Install the carrier and shim it for the correct backlash
Mark the ring gear with grease in three different places
Get someone to put pressure on the axle or ring gear and then turn the pinion forward and back ward a few times to mark the pattern
Then if you can't get a good pattern on the drive side, set it up for a good pattern on the coast side