8.5 in rearend

doood

Amateur Mechanic
Sep 24, 2020
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Thread file may help.

In the case of the yoke may have to try google and see what the threads may be. Most likely Metric M8x1.25
I tried the metric bolts, both fine and coarse - neither worked. Ran a 5/16-24 tap through the holes and the new bolts thread-in correctly.

I'm sorry I've never experienced that; never seen such corrosion. Thanks all for advising me
 
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doood

Amateur Mechanic
Sep 24, 2020
586
799
93
I've got some good videos, and a "how to" book, but does anybody know where I can get an actual service manual for any GM 8.5"? I understand I should have 0.005-0.009" backlash, 14-19 in-lb of pinion bearing preload, good pattern, etc.

I just measured like 2.5 in-lb of torque to turn the pinion with the ring gear and carrier still installed (no spider gears or axels present). That is quite far below spec for used bearing per my reference.
 

doood

Amateur Mechanic
Sep 24, 2020
586
799
93
Preload is not the same as turning resistance.
What are you using to measure the drag on the pinion
An 0-80 in-lb beam-type torque wrench.

My references are telling me I should see 14-19 in-lb after I put it back together with new gears and bearings. I'm seeing like 2.5 in-lb with the ORIGINAL equipment (empty carrier, no axels, etc.).

I am practicing the motions on the original build that I am tearing down - I'm going to take a contact pattern tonight, measure backlash, before I take the carrier out and take the ORIGINAL pinion and yoke out.
20240205_122125.jpg
 
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doood

Amateur Mechanic
Sep 24, 2020
586
799
93
If you have used bearings and gears they won't as be tight as new ones. That's a no brainer...
I'm just sharing... didn't expect nil resistance. Was hoping to get a bit of practice with reading the torque wrench while spinning it. I've become very farsighted in the last two years and I can't see s*** up close
 

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