Rear Axle Identification

Injectedcutty

Injectedcutty

Comic Book Super Hero
Nov 24, 2014
3,513
8,673
113
Louisville, KY
#71
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

Rktpwrd

Royal Smart Person
Feb 2, 2015
2,052
6,733
113
Calgary, Alberta, Canada
#72
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

ssn696

Comic Book Super Hero
Supporting Member
Jul 19, 2009
3,582
2,424
113
New Mexico
#73
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.
 
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tricrick84

Not-quite-so-new-guy
Aug 3, 2016
7
0
1
#74
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

pontiacgp

Canadian Prime Minister
Mar 31, 2006
24,750
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Kitchener, Ontario
#75
do you have both bearings for the pinion installed?
 
T

tricrick84

Not-quite-so-new-guy
Aug 3, 2016
7
0
1
#76
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

pontiacgp

Canadian Prime Minister
Mar 31, 2006
24,750
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Kitchener, Ontario
#77
then I do not understand how the pinion is rubbing the housing....pictures may help
 
T

tricrick84

Not-quite-so-new-guy
Aug 3, 2016
7
0
1
#78
top one is the regal differential and the bottom one in the new one.
original-regal-diff-jpg.53292
chrome-cuttlas-diff-jpg.53293
 
pontiacgp

pontiacgp

Canadian Prime Minister
Mar 31, 2006
24,750
10,213
113
Kitchener, Ontario
#79
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
 
T

tricrick84

Not-quite-so-new-guy
Aug 3, 2016
7
0
1
#80
Shiiit. That makes a whole lot of sense. Would you happen to know what it would fit on?
 

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