GM 8.5 10 bolt swap from a 96 impala ss

After months of searching for a 94-96 rear end with disc brakes from either a 9c1 or impala ss, i found one an hour and a half away from me, so i jumped on the highway and bought that sucker. For 300 bucks it was mine. It came from a 96 impala ss, mileage is unknown which is why i got a deal on it from the junkyard. They originally wanted 550 for it. I will have to do an overhaul on everything, rotors, calipers, hoses, etc. But im going to por 15 it, drain and refill with fresh oil, and new cover. It doesnt seem like the posi works from the simple spin the wheel test, its acting like an open diff, with one wheel spinning the opposite way. I do believe it is an auburn cone type posi, which means its not rebuildable. The thing was covered in mud and rust, looks like it has sat for a few years. I didnt get to see the donor car, i wish i could have. But ill get that 9c1 control arm kit for like 45 bucks since they cut the control arms! But they gave me a sway bar so i have two of them now, not sure if i should keep it or scrap it, obviously i dont need two. It will be a few months before install, ill have to get a new master cylinder with a 1 1/4" bore to upgrade the 1 1/8" bore mine currently has and also a proportioning valve for the rear discs, and have the drive shaft shortened. Also since im not changing wheels right away ill have to use an adapter for my bolt pattern, its going to be some work, but ill keep yall updated. And as always heres some pics.









somehow a plastic bag got twisted in with the yoke, so ill have to replace the pinion shaft seal, which is a no biggie

UPDATE 3-30-14

Got the rear end sandblasted, primed and painted. All new seals, calipers, rotors, brake pads, brake hoses and outer pinion cone bearing on the way. I think im going to paint it gray or silver, i like black, but we'll see. Im hoping to have it in possibly late next month or some time in may. Everythings going smooth and i cant wait!

Looking good!

Very nice. I love the blue jean supports.haha

Hey gotta do what you gotta do! lol, no i actually ran out of rags and towels, so old jeans were next lol. And ive found good use for empty paint cans too

Alright, rear end is all done, restored to its former glory, just waiting to be put in.

THAT is a thing of beauty right there. Great job!!

Sweeeeet!! I'm jealous!   

Alright, she's all done! Huge huge improvement from the old rear. You can feel that 3.08 lol Thats a huge jump from a 2.41 to a 3.08, and its def noticeable, same with the disc brakes, another huge improvement from the stock 9.5" drums. It was alot of work but well worth it.

My journey:

You're brave using that scissor jack. I hate those things and they hate me too.lol The underside of your car looks good and solid, much better than mine does as far as the pans. Nice job on the install!!

I was pretty nervous the whole time, i couldnt wait to get it done, but i got to get a new floor jack so that scissor jack was all i had. Yeah the underneath isnt bad at all, the frame is a bit rusty but the body has no rust. Im just glad its done and everything went according to plan. It went pretty fast too, it only took a day to swap them out.

Oh yeah, one thing to point out that i forgot to mention. When changing from the 7.5" rear end to the 8.5" rear end, the drive shaft has to be shortened, and to my surprise it needed to be shortened exactly 1 inch.

I'm trying to figure how I'll make out with 455/th th-400 (longer ns how much yet) and an 8.5 I can grab a RM driveshaft

but that comes from an LT1\ 4l60e (no idea on length) I'll have to measure everything this week. Are you having it shortened then ?

I use to live next door to place in Albany that did that everyday up here I'll be hard pressed to find a place may have to go to Albany.

Looks great! I am looking for the same rear end to swap into my 78.



Geno

bgkid2966 wrote:Looks great! I am looking for the same rear end to swap into my 78.



Geno

Welcome to the forum.

These guys have a 96 Impala SS rear end.  They're real close to you too.

http://www.globalautorecyclers.com/

Sweet Seventy9 wrote:

bgkid2966 wrote:Looks great! I am looking for the same rear end to swap into my 78.



Geno

Welcome to the forum.

These guys have a 96 Impala SS rear end.  They're real close to you too.

http://www.globalautorecyclers.com/

Thanks, I will be calling them tomorrow!




Geno

Sweet Seventy9 wrote:

bgkid2966 wrote:Looks great! I am looking for the same rear end to swap into my 78.



Geno

Welcome to the forum.

These guys have a 96 Impala SS rear end.  They're real close to you too.

http://www.globalautorecyclers.com/

Thanks for the welcome! I am glad I found this forum!

Thanks, I will be calling them tomorrow!




Geno

They do have the rear end and they are proud of it! $500 is way too rich for me right now. I will keep my eyes open for more to pop up though.



Geno

bgkid2966 wrote:They do have the rear end and they are proud of it!  $500 is way too rich for me right now. I will keep my eyes open for more to pop up though.

Geno

There's a list of rear ends that will fit our cars in this thread - https://www.gmbbodyforum.com/t205-rear-diff-interchange

I bet you can find something besides the Imp SS one at one of your local yards.

I hope this helps.

Just found me a ss axle of a 96.
Should I wait and order new rotors pads bearing and seal kit first ..or just clean up the brakes it has and just change the gear oil and slap it in.
Car looks like it was a driver before just missing grill and corner light probably fender bender casulty
Also since it's a 5x5 pattern and older caprices run 4.75x4.75 patterns has anybody tried carefully drilling the holes in the rim larger to fit .. I have a spare to practice on any input helpful just can't wait to do some two wheel peels

Do NOT drill your rims! It is not safe! I would get replacement rims. Just the right way to do it.




Geno

I would just replace all the stuff while its out and easy to get to, thats what i did, only one of my axle seals was leaking but i did them both, theyre not expensive and easy to do. As far as the bolt pattern, do not drill new holes unless you have an exact pattern of the 4.75, the bolts have to line up perfect. If you cant do it, you can take it to a shop to do it, or order new axles that have both patterns from Moser. Or a cheaper route which is what i did, buy some wheel adapters, i put 1.25inch wheel adapters on from a 5x5 to the 4.75 that my wheels are. But thats only if you have enough clearance for the spacers.

I agree, drilling your own holes is dangerous. 5x5 "Steelies" are only $20 each around here. There's a gozillion of them out there from full size GM cars. (roadmaster, seville, olds custom cruisers, etc) Check your local salvage yards for them. Heck, I see them on C-list all the time too.

Even drilling the hub on axles is better many people do that rather than drilling the wheels that's a no no.

Thanks for the input just went today to scope out the impala and even better than I though it had no accidents. It was immigration police impound from a pollito (lil chicken in Spanish/ the person who crosses people across the border illegally)
Looked at the rear looked solid and had the posi tag on the cover.
Gonna hit up the junkyard for the rims ..don't really trust wheel adapters.