I'm installing a used GM ring and pinion in my 10 bolt diff. The original, stock pinion shim was about .035. The pattern I'm getting says I need to decrease the shim thickness but I'm already down to .025 and the pattern is not moving much. I've got the e-brake on to create drag but perhaps not enough. Is there anything else I should look for? I was a virgin going in to this. Pleae help.

 

Put the same shim back into it that the housing came with.

Gears are all the same, within a couple of thou (except for the Richmond drag-race ones). You're not shimming the GEARS, you're shimming the HOUSING. It just happens that the shim to make up for the potentially WIDE variation in housings, is located on the gear, instead of behind the outer race where it really ought to be. Reason being, it's cheaper for the factory to assemble them if they put it there.

Don't worry about the pattern. Put the .035" shim back in, and set the backlash correctly (.008" - .010" with used gears). Run it.

 

Thanks Sofa, but found my problem, dumb rookie mistake. Ain't even gonna tell you what it was so you don't point and say Dumb Canadians. Oh, and and as you said, the .035 shim worked great.

 

What makes you think some dumb person like me from some other country would say that?

 

lol