removing rear end from '90 Caprice

[deesandvees]

what are the necessary steps to remove the whole rear end from a '90 Caprice? I'm making a junk yard trip tomorrow and want to make sure I don't come home empty handed because of one missing tool or anything small like that. Thanks.

[DANZIGS]

Sockets for the drive shaft, control arms, remove coil springs, lug wrench, snips for the brake lines, PB Blaster....porta-torch

[silicon212]

Snips for the brake lines? NOOOO!

There is one line that connects the axle with the brake system - this is in the center, on the top of the diff housing. It connects to a tee that distributes the brake lines to each wheel.

Simply disconnect the line.

You will need an 11mm socket with a LONG extension (to make it easier to use a ratchet handle near the driveshaft), or an 11mm box wrench and some upper body strength. You will need a jack, two sets of jackstands, 18 or 19mm socket for the shock nuts (some are 18mm some are 19mm), a 21mm socket and a 21mm box wrench for the control arm bolts, the proper socket for the rear sway bar (if equipped, these are either 17mm, or 19mm can't remember exactly which), and patience.

Start by jacking the car up. First, remove the driveshaft. Mark one area of both the shaft and yoke so that you can put the driveshaft back in the proper balance. Now, remove the shock nuts, and then separate the shocks from the axle tubes. This is best done by jacking the car up one side at a time, just enough to take up the shock travel and no more. By now, you should have both sides of the car jacked up, tires removed, and secured with jackstands. Once both shocks are removed from the axle tubes, the springs can easily be removed. You won't need any tools - just lower axle down as far as you can and the spring should come right out. If you can get someone to help by LIFTING the opposing side, this can make the job easier. The second spring will be easier to remove, due to the fact you won't be facing resistance from the first.

Once the springs are out, use the jack to raise the axle assembly up - just high enough to put a jackstand under each tube, at the lowest possible lift setting. Lower the axle onto the jackstands until they are supporting its weight. Remove the brake line fitting from the tee on the top of the diff housing. Plug the line with a special, for-the-purpose rubber plug - these are available at auto part stores for a nominal cost. Remove each control arm bolt - 4 in total. You will need the 21mm socket AND box wrench for this. Once all 4 are off (only remove the control arms from the diff/axle assembly, leave them connected at the other points unless you wish to replace the bushings - not a bad idea), the axle should simply slide right out from under the car. A 7.5" axle weighs about 75-100 pounds, the 8.5" easily weighs at least twice that. You should be able to lower the axle off of the jackstands and slide it out.

Installation is the reverse of removal, with the added step of bleeding the rear brakes when you are done.

[deesandvees]

So this posi rear has a 5x5 lug config and mine's got the 5x4.75. If I want the 5x5 for the front to match is it as easy as getting new rotors?

[silicon212]

Originally Posted by deesandvees

So this posi rear has a 5x5 lug config and mine's got the 5x4.75. If I want the 5x5 for the front to match is it as easy as getting new rotors?

Rotors and spindles - you can use the calipers you now have, but they are located a little higher on the spindle for the larger rotors.

[deesandvees]

Also, I haven't removed the diff cover off either car yet but is there a way to know if I'm dealing with a 7.5" or a 8.5" from the fact that the pumpkin is about 11" tall and it's got 10 bolts?

[silicon212]

Originally Posted by deesandvees

Also, I haven't removed the diff cover off either car yet but is there a way to know if I'm dealing with a 7.5" or a 8.5" from the fact that the pumpkin is about 11" tall and it's got 10 bolts?

There are machine pads, or 'ears', cast into the diff housing on the bottom, on each side. These pads have a 'half drill' pattern machined into them on the 7.5", where on the 8.5" they're pretty much unmachined. The following images illustrate this:

7.5"



8.5"