: what other rears fit my 82 coupe deville?



turbocaddy
01-14-07, 11:21 PM
my 82 rwd coupe deville's rear is slowly dying, what other makes and models will fit? I see the driveshaft has the big flange on it but will another make model fit with another driveshaft?

patgizz
01-16-07, 03:55 PM
77-96 B + D body coupes/sedans. the wagons are wider and the 94-96 SS impala is 1.25" wider. driveshaft needs changed for all but from a caddy because of the flange vs yoke on the pinion

where you at? i just pulled the original great shape 80k mile deal from my 79 and put in a 96 SS disc brake posi unit.

caddydaddy
01-16-07, 08:21 PM
77-96 B + D body coupes/sedans. the wagons are wider and the 94-96 SS impala is 1.25" wider. driveshaft needs changed for all but from a caddy because of the flange vs yoke on the pinion

where you at? i just pulled the original great shape 80k mile deal from my 79 and put in a 96 SS disc brake posi unit.

I also put a 96 SS posi rear into my 79 SDV, and I just changed the flange. So the 79 flange is on the 96 rear.

Benzilla
01-16-07, 08:25 PM
Doesn't the SS rear have better gearing? So did you get a performance boost?

patgizz
01-16-07, 08:25 PM
didn't know they interchanged. that'll save me some cash.

N0DIH
01-16-07, 08:41 PM
You can interchange the entire axle, but you can't swap internal parts.

patgizz
01-16-07, 10:49 PM
yeah i was referring to the yoke/flange for the driveshaft.

the caddy has the goofy cad only 12 bolt and the SS is 8.5" 10 bolt

The Ape Man
01-17-07, 02:47 PM
Flanges can usually interchange but extreme care must be used. If the new flange is more than a few thousandths deeper than the old one OR if the nut gets overtorqued then the crush sleeve will get crushed more than it should. This will alter the pinion depth. All that said, after a dozen swaps only 1 gave me trouble. I landed up having to torque the nut a lot less than the original and had to grind another nut to half it's depth and install as a jambnut.
A lot of axles will swap into your car. You can even use Olds, Chavilay, Buke and Poontiac but the bolt circle on the rims is usually smaller than Cadillac. Some space saver spares have both bolt patterns so you can still have a spare which fits everywhere.

turbocad6
01-17-07, 02:53 PM
I have an 83 coupe with a beefy grand national engine in it, I redid the stock rear with an eaton posi unit with best of everything build, & I used a pair of strange axles... this should be good well into the 10's....., maybe not the cheapest way out though...

turbocaddy
01-18-07, 10:37 PM
that's funny ,I run a gn drivetrain also, the stock rear axle bearings are wearing off the axles and axles are a pain to get...what part # or model axles did u get and what rear posi fits? what model rear do I ask for to get parts?

turbocad6
01-20-07, 08:52 PM
I don't remember,,, strange will want dimensions & spline count & stuff... the posi unit was a 30 spline 8.5" unit if I remember correctly..., been a while...

turbocad6
01-21-07, 12:47 AM
do you still have the stock housing & is it good? are you doing anything else like suspension or baby tubs?

best thing is to talk to a supplier or a race car builder... it mighta been a 32 spline or 33 even, you will have to check the splines unless your going to go axles & pumpkin at the same time which is best... I had an aubern summit special first, but it didn't even last one season, buy the 3rd time I ran the car only one wheel was spinning, then I just went for a real good unit... I think I got it from a place named thomas axles or something... there was a great writeup at the time in hotrod mag & I called the guy up, told him what I wanted & he built it, was like $900 though, but I never had any problems since, & I ran it alot... they mighta been in florida... I'm sure there are many good companies to talk to

I also used a ta cover that adds a bit of strength to the housing....

how fast is your car? do you race it with slicks or is it always on the street tires?

N0DIH
01-21-07, 02:34 PM
The axle Cadillac used isn't a 12 bolt, has no relation to the Chevy 8 7/8" 12 bolt. It is the Pontiac designed 10 bolt axle common on the 71-76 B/C/D cars and the 77-84 D cars. In 71-76 it had the 8 7/8" ring gear and in 77-84 it was a 8 3/4" ring gear. Range of ratios is 2.41 to 3.23 with the 8 7/8" ring and 2.28 to (I believe) 3.08 for the 8 3/4". Only a cone type posi was ever offered and are quite rare.

They are in no way related to the Chevy 12 bolt that was used in big block cars. Pontiac axles that I have seen all have had a 8 bolt flange on them.

To install the other axle you will possibly need to change the driveshaft for length and flange. Just get it front the donor car, or talk to a driveshaft shop.


yeah i was referring to the yoke/flange for the driveshaft.

the caddy has the goofy cad only 12 bolt and the SS is 8.5" 10 bolt

turbocaddy
01-26-07, 09:51 PM
my caddy runs 14.7 in a 1/4 mile, single rear, mostly a street daily driven car...it's been together for over 10 years and has 196,000 miles on it now..
the axle bearings are wearing out the axles and it seems the housing is worn out larger than a replacement bearing...oil leaks out and on to the brakes...