Factory 8.5 rebuild ????

Getting the clutch packs in can be a complete PITA. Especially because you have to get the right stack height and you never really can.... My .02 is don't rebuild the factory carrier if you haven't done it before.

Have you checked the clutch packs yet? I have an Eaton in my 67 rear end with the original clutch packs and they still grab like they are new. I know the clutch packs in the rear are original cause the thrust washers which had a service bulletin to change were never changed

I have a '78 GM 8.5 truck axle with 4.10s. I put it under a back-half trailer and that thing does not like to turn when pushed around by hand. $500.

bertscova said:

I haven't even opened it up yet. Its not in the car yet. I was going to replace all the bearing before putting it in the car. So while it was apart thought i would replace the clutch packs..

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I checked mine out and all the bearings were good so I just changed the thrust washers and put it back in. Bearings are easy to check and if they are good I trust the original parts better than what you can get now.

bertscova said:

I got a motive gear rebuild kit has all timken bearing. Was only 90 bucks.

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Take them out and look at them. If you're not sure if they are worn, then post a couple of pics. It can be considered a pain if the diff is in the car, but having it secured in a vice makes it go a bunch simpler. Just keep track of what clutches and shims came from which side. Also measure the total pack thickness dry (YES DRY) meaning you have to clean them and measure them. Also measure your back lash, carrier preload, and check your gear pattern prior to disassembling. If it is all in spec, then most likely it will go back together in a jiffy. If it's out of whack before you tear it apart, then you can adjust from there.

Sidebar: would someone be willing to post the year breakdown and ring gear sizes?
From my understanding:
10 bolt 8.2= early 60s thru late 70s
12 bolt 8.5(?)=early 60s thru late 70s
10 bolt 7.5 picks up where the 8.2 left off
10 bolt 8.5 does the same....
Is this close or can someone clarify?