Rear end troubles

[Tony]

I do some differential work and that 12 bolt looks a bit beat up. but nothing that new gears and bearings won't fix..

[davepl]

Originally Posted by hamjet

"""but they are on national backorder""" is this because its a defect/common thing happening to the vets?

That's the rumor. Apparently it started in 2014, and the reason is supposedly to be low fluid fill at the factory.

So you think they'd catch that at the dealer PDI, but I made them keep and give me my sheet, which showed a bunch of nonsense. Every box was checked, including my transfer case (on a Corvette) and clutch (automatic) and washer fluid (empty) so I don't have much faith in it.

Oddly it was quieter yesterday. I don't know much about gears, I've had 20 cars and never a failure no matter how old and abused.

As for posing, here's a pose with both the truck and the car - 45 years of GM engineering, and the rear ends still break. Actually, the Dana60 in the truck is bulletproof now that I think about it.

[davepl]

Originally Posted by Tony

I do some differential work and that 12 bolt looks a bit beat up. but nothing that new gears and bearings won't fix..

Here's what little I know, I'd love if you'd fill it in - transmissions and 12 bolts are the two things I try not to take apart.

- Check backlash with micrometer
- Change shims left and right to correct (watch your fingers dropping it in!)
- Fill with fluid

But if you've done it with the micrometer, do you still need to do the contact pattern paint thing? It sounds like plastigauging after you've mic'd a journal.

[Later Edit: As so kindly pointed out below, while a depth micrometer can be used, a dial indicator is much easier though less accurate. The normal way is indeed a dial indicator on a magnetic base but I'd then use the contact pattern paint to be sure.]