So after nearly rolling my car off the highway...

[64sabre]

Car is surprisingly solid. Crushed the bottom of the drivers side rear quarter panel. Shifted the bumper two inches up on the drivers side. Drivers side exhaust got bent over to the passengers side. None of it a big deal.
Unfortunately, I straightened the backing plate, fixed the drum breaksthen put, tires on the rear (while on jack stands) so I could run it and see if the tires would roll straight, hoping the axe wasn't bent. When I ran it, the drivers side tire rolled fine, while the passenger side rolls forward a few inches then stops suddenly and won't move. While in drive, with the drivers side tire moving, I can grab the passenger side tire, easily roll it backwards a few inches, then it suddenly stops again. When I let go, it moves forward again, but after rotating a few inches, it comes to a sudden stop in the same place it initially did.
I don't have much experience with rear ends, but I assume this means it junk.
The rear end is the 9 3/8". I was told it is posi, but I can't find any markings to confirm this.

So is the rear end able to be saved? If I switch it out, I doubt I can find a match, so I just want one that's the right width (54" backing plate to backing plate) and weld on the brackets myself. If I go that route, what's a good one to keep an eye out for? I have access to a ford 9" for $100.
Also, while trying open up the rear end, I was unable to get the cover to separate from the housing (cover faces forward and has drive shaft running through it). Any thoughts?

Thankyou in advance.

 

[bob k. mando]

verify that there's nothing caught in the drum.

then, pull the diff cover and inspect. could be a busted spider gear or carrier. if it is, you'll likely need to source a used axle as there are NO repro parts for any of the various 9 3/8s designs.


i would suggest not running the driveline til you get this figured out. posi rear ends aren't designed to 'free wheel' one side or the other for extended periods of time. if it really IS a posi, you're tearing up the clutch plates by doing this.

 

[64sabre]

verify that there's nothing caught in the drum.

then, pull the diff cover and inspect. could be a busted spider gear or carrier. if it is, you'll likely need to source a used axle as there are NO repro parts for any of the various 9 3/8s designs.


i would suggest not running the driveline til you get this figured out. posi rear ends aren't designed to 'free wheel' one side or the other for extended periods of time. if it really IS a posi, you're tearing up the clutch plates by doing this.

I tried pulling the cover, and it won't come off. I removed all 12 bolts, and the big nut in the center that sits inside the driveshaft flange. It comes away from the housing about 1/4" and then stops. Won't budge anymore. I can pull the top or bottom out further, to about 1/2", but then the opposite end shifts back against the housing. Can't figure out why it won't come off.

 

[raycow]

You have to pull the axle shafts out before you can remove the center section. If you know how to take out the Ford center section, the Buick comes apart the same way.
This assumes your car matches your username and you really do have a 64.

If you do end up needing to replace the rear, measure the width over the drums. You want wheel mounting surface to wheel mounting surface. The backing plate measurement doesn't tell you anything useful.

Ray