Can someone confirm these Motive Gear pinion bearings fit our cars...

I would suggest contacting Steve V's or Bison's the kit looks correct as pictured but and with the crush sleeve you are going to have some dial caliper work to do as well to get the preload correct. I have done preload pinion work by just garbing the pinion and guessing at 5 thousands of play but I wouldnt recomend it on an 86-87 GN diff. I would recommend those 2 folks I mentioned as they are the experts that i am aware of. This job can grenade your diff if you are out of tolerance.
 
I would suggest contacting Steve V's or Bison's the kit looks correct as pictured but and with the crush sleeve you are going to have some dial caliper work to do as well to get the preload correct. I have done preload pinion work by just garbing the pinion and guessing at 5 thousands of play but I wouldnt recomend it on an 86-87 GN diff. I would recommend those 2 folks I mentioned as they are the experts that i am aware of. This job can grenade your diff if you are out of tolerance.

As info the way to get pinion bearing preload is by using an inch pound torque wrench to measure rotating torque of the pinion gear after the sleeve is crushed. Different specs for new vs used bearings. Then ring gear backlash is measured with a dial indicator. Then comes the pattern check with gear marking compound.
 
As info the way to get pinion bearing preload is by using an inch pound torque wrench to measure rotating torque of the pinion gear after the sleeve is crushed. Different specs for new vs used bearings. Then ring gear backlash is measured with a dial indicator. Then comes the pattern check with gear marking compound.
Wut he said^^^
 
There is three different size pinion bearings for an 8.5 the newer Chevy trucks use a larger bearing and still has an 8.5 rear best bet is to remove the bearings and go off the part numbers they're usually in stock at most part stores
 
I called Motive Gear. # R10RTPK is the part number for our cars. It comes with Timken pinion bearings. This should help others with future searches.
 
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