ziff396

Awile back (it's still cold outside!) I set up my new gears and wanted to make sure of the tracking with the original pinion shim. I got lucky and everything was fine along with the backlash. However, the passenger side factory axel shim with the chamfered edge has a crack in it. Should I build up shims from my bearing kit, or would the original still be okay? Street driven. (Someday)
Thanks

Danny Wiseley

If you are referring to the side carrier bearing preload shim, I would NOT reuse a cracked one. In fact, I'm almost certain I read in a factory manual to not reuse the cast one even if it still looks good, but to use the steel shims only.
dw

Run to Rund

GMPD offered .170 thick steel shims to replace the cast iron production shims. It would be better to use them or have something made up from heavy wall tubing of the correct diameter instead of stacking up a boatload of thin shims.

ziff396

Thanks! Yes they are the carrier shims. I'll go ahead and replace both of them. I did"nt know they were available. I'll then re-check my pattern and backlash.

Run to Rund

Shims are in group 5.537 and the spacers are in the same group, listed separately in the 1973 catalog. I don't know which rear you have. 9780883 is for the 12 bolt type C and some others. 9775809 is for Type O and P.

ziff396

It's a 72 corporate 10 bolt 3.42 posi.

monzaz

Well I can tell you the that the cast shims will NOT accordion like a bunch of steel shims sandwiched. The BOP shims were very thin from inside to out side diameter compared to chevys more doughnut style thicker from inside to outside diameter like about 1/2 " compared to the BOP 1/4"...

I use the cast shim as much as possible in all the builds. The thicknesses are more precise They make new shim packs call super shims which ad in keeping the shims sandwiched when install then in the carrier pocket.

Good luck on the builds. Jim

J D Race.com

Run to Rund

According to GMPD, use the type o,p shim 66-72.

ziff396

Thanks again for all the information! I do have some thick shims that came with my kit. I'll also check into the GM one's.