Sooooo,
While adjusting the parking brakes I found this.



how much fun is this going to be to fix?
Thanks for any insight.
Mark

 

Found the same prize on mine a few years back

Its a chore, but its not that bad....you have to remove the spare tire cover, rear spring, and then drop the crossmember above the rear.
Get a heavy duty one.

 

That is a major "While I'm at it" project.
You'll be close to the half shaft u joints so you may want to change them.
You may need strut rod bushings and drive shaft u joints.
Might as well get new trailing arm bearings.
And the most costly will be once you get a look inside the differential and decide to rebuild it!

 

Remember, when you get it all back together, to torque the bolts to the spec, and no more. King Kong must have cranked those puppies on to have cracked both sides like that.

 

Hey BP 77,
Feel for you Man.

This is the bane of later car owners. Unless you are experienced and have a good checklist to review when inspecting a potential buy, small issues like this might not be noticed until it's too late.

Then, they can be costly to repair. Just the "while-I'm-at-its" to get to the initial repair will increase costs exponentially. At least this one is relatively common and you have multiple resources for help.

Thanks for the pics. Can we see more when you decide how you'll have the project planned/repaired?

Good luck.

 

I have what appears to be a brand new HD rear cover with the thicker ears, if you or anyone else is interested send a PM...$100 owns it.

 

Remember to only torque the spring mounting bolts to the differential while there is weight on the tires/suspension. If you torque those bolts while the car is in the air or on jack stands, then when the weight comes back down, it will crack the diff cover, again. I believe that is the GM procedure as well.

 

Thanks for the help. I have the diff down, and painted. Thinking about repainting it blue(thoughts?), not sure if I want to do that or just leave it black. I really do not want to pull the half shafts and strut rods off and repaint them just now. I want to cruise...

as requested --
sheared ears

dropped



painted

 

That's coming along very well.
There is a lot of posts on yokes and snap rings, how about a picture or two of that area?
How many miles of that rear?

 

Mark, if it isn't too late... try to gently pull the Differential Side Yokes out of the differential. If either of them does slide out more than a half inch (it will probably then come all of the way out) it means that the clip from the end of the axle has broken and this will need to be addressed before reinstalling the differential.


Also as others have mentioned, when reinstalling the rear spring to the rear differential cover, tighten the bolts until they are snug only, do not torque them yet. Once the ends of the spring are connected to the swing arms and the car can be lowered to the ground (weight of the car is now flattening the spring) you can finally torque the bolts as recommended. You can lower the tires onto some ramps or large blocks of wood to give you the clearance to get under the rear to the spring bolts. The important thing is not to torque the spring bolts until the weight of the car is flattening the spring. Otherwise if you're lucky you might only pull the threads from the rear cover...

Also, if you are going to use new bolts here (grade 8 of course) be sure they are the correct length. The forward bolts go into blind holes in the differential cover and if they are too long, they can punch through the cover into the rear.

Good luck... GUSTO

 

Thanks again.
yoke endplay measurements are .020 and .026 inches
both snap rings look like they are nearly new, no deformation/discoloration.
yoke shoulders appear to exist, so I think the endplay mostly due to pinion wear.
I looked at this thing for quite a while for abnormal wear/discoloration cracks etc and it appears ok.

This rear has less than 67000 miles on it.
I think I am going to button it back up and put the gear lube in. I did not change the clutch packs, do I need 2 bottles of LSD additive or just one?

Copy all about when to torque leaf spring, thanks.

here are 2 pics-

and a closer look-



bp

 

Had the same thing happen to my 73. Replaced it and the leaf spring(used a composite) at the same time. Rides fantastic now and I feel a lot safer too.

I used 1-4oz bottle of additive (from the GM dealer) in the differential. Add it first, then fill with the rear end with a brand of your choice. Mine took slightly over 1.5 quarts.

Fran

 

Yeah, those yokes are OK, you'll be fine.
One bottle of additive should be sufficient.

 

Thanks for posting pic's of the inside.
I agree, just close it up and enjoy!

 

Hi i think my snap ring is broken has excessive play passenger side
Is this going to cause an problem ,hoping to do rear end rebuild in a few months just wanted to drive for now
thanks Ian