Rear Diff Questions 82

Hey, I don't have any intention of stepping on anyone's toes but even in stock configuration they're not the hot steaming piles of crap so many people make them out to be. They may not be able to handle massive amounts of torque but even for spirited driving with moderate amounts of power, they seem to do just fine.
My original '81 2.72:1 diff lasted for years we me hammering away at it at various autocross and track events and only failed after I took it to some half assed local shop to rebuild it. (I pulled it to fix leak and discovered the exact thing the OP is seeing. I think this is truly the worst part of the design.) The 3.07:1 out of an '80 that I used to replace it has been in the car, and probably 20k miles (2 to 3k of those on a track) with nary a problem. And lately the car has been putting about 300 horse to the ground.
Granted, I don't launch the car like a drag racer. Road Racing practices die hard.
Considering I don't intend to put more than 400 to the wheels, I will probably just have my current one rebuilt at some point during the restoration.
 
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What a controversy! But the truth is everyone is correct.
It's not a bad diff but it sure has it's problems. The metal thickness is all over the place. I have not seen two alike with the same internal measurements. Cap thickness varies drasticlly, which is why some break easily and some last forever. The internal bearing step is a work of art. And it should be in the museum of "What were they smoking when they thought of this". Same with the clutch disc retainers. And the rear pinion bearing race sticking out of the bore .050.
But it's all repairable. I've never seen a carrier break or a stub axle twist off. Everything internally is larger than the iron diff. I still would not put it up against one of mine or Gary's Super 10's but for the person making 450 hp and doesn't want to spend the extra $800+ to do the conversion it will do fine.
Mike
 
hbz_81_c3 said:
. I plan on taxing the aluminum differential to the limit with the addition of juice foggers in the intake.
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Interesting thread to read. Can you provide some information about the aluminum differential? I know Tom (Differentials) has been saying he's going to offer an aluminum billet differential case. Is this something from him? Is it a 82 aluminum differential case? Something else altogether? Thanks.
 
Interesting thread to read. Can you provide some information about the aluminum differential? I know Tom (Differentials) has been saying he's going to offer an aluminum billet differential case. Is this something from him? Is it a 82 aluminum differential case? Something else altogether? Thanks.[/QUOTE]

It is a '81 differential built by Mike.
 
Hi John,
Tom's aluminum diff will be based on the iron diff and will allow the use of a 3 series 12 bolt carrier. But you still won't be able to use the 12 bolt setup in an 80-82 because it won't clear the batwing.
Mike
 
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