Rear Axle Identification

[Injectedcutty]

I'm going to look at a non-running 1986 442 tomorrow; If I were to pick it up, and bolt in the 8.5, would the driveshaft proper fit from a 200r4-8.5 to a TH200-7.5?

Thanks!

Don't believe so, the 8.5 has a longer pinion on it requiring the driveshaft to be shortened about an inch. At least i had to shorten mine an inch when i swapped out my 7.5 in my 87 cutlass to a 8.5 i got from an '85 442 with 3.73's in it. Hope this helps.
Scott.

 

[Rktpwrd]

If you can, grab the driveshaft out of it when you grab the diff. Problem solved. That's what I did.
As far as the difference between the slip yokes from a TH200r4 to a TH200, I can't say. I went from a TH350C to a TH200r4. Maybe some other members can say yay or nay.

 

[ssn696]

TH200C uses the same 27-spline slip yoke as the 200-4R, 700-R4, TH350 and TH250. The one that is different is the TH400.

I did just climbed under my coupe to measure the 8.5 yoke. It seems to use the same 534G U-joint as the 7.5, with the inner lock rings that fit into a groove in the caps. And I can back up that inch. That's about what it looks like I need to take off according to my current driveshaft. Just get the rear end of the driveshaft tube shortened and rewelded. I suggest new U-joints and a dynamic balance.

 

[tricrick84]

i bought a 84 cutlass 7.5 differential and tried to fit a 84 regal limited slip gear into it. the pinion started rubbing on the housing. would anybody know how to solve this problem?

 

[pontiacgp]

do you have both bearings for the pinion installed?

 

[tricrick84]

do you have both bearings for the pinion installed?

yeah, we had a hell of a time banging in the racer for the inner bearing, but we finally got it in.

 

[pontiacgp]

then I do not understand how the pinion is rubbing the housing....pictures may help

 

[tricrick84]

top one is the regal differential and the bottom one in the new one.

 

[pontiacgp]

the lower rear is an 8.2 and that's why the pinion does not fit..and it will be wider than your G body rear

 

[tricrick84]

Shiiit. That makes a whole lot of sense. Would you happen to know what it would fit on?