looking for advice on a reinforced diff. I run a 03 AP1 with a comptech SC w/AC.
The car is a track only car and I am still running the stock diff. I think I can start to hear it
make a bit if a clunk when I put it in gear and when I shift hard sometime.

I should note that the car has no interior at all so it's really noisy in there and I could just be
imagining it. Seems like every time I read something on this forum I think it's happening to my car.

I'm a hypochondriac when it comes to noises in my car, bad quality when you have no interior.

 

I am SC'd and track my car. I had clunking in my diff but that's not caused by driving on a road course...it's caused by a bit more strain on the diff driving around town and accelerating hard from a stop, etc...

I replaced my rear diff with another OEM unit and I don't have any other issues. You can accelerate as hard as you want with the SC...just don't do clutch drops from stop lights.

 

I had the same problem with mine. I am over 500 rwhp and even with no clutch drops there was a problem. I have 4.57s and a comptech reinforced housing. I took the rearend out and found the crush sleeve that sets the pinion was crushed a little more than is used to be.

Now I went back to 4.10s with reinforced housing and cryogencally thermal cycled the whole diff. LSD, Pinion, housing, everything.

I would recommend checking your rear.

Clunking is not normal!

 

I'd recommend opening it up, you probably have broken teeth in the diff itself. Trust me, it happend to me, and I was going 25 mph and driving like a sane person, and it just blew up on me. Metal chunks everywhere.

I went with PuddyMod Racing diff. He can show you pictures of the 3 (stock, comptech, puddymod), his reenforcement is much larger, and I bought his personal diff, with the 4.56 gear set cryotreated, which is what I would recommend to you. LMK if you need any more info. I've had my diff for about 2-3 months now, and it's great! Only a little whine when slowly accelerating!

 

A PuddyRacing diff is the way to go.



[removed krazik]

 

several choices

1. stay oem stock and hope about 600 used

2. Sub Zero cryotreat the oem diff about 200 with new seal and setting pinion

3. cryo and reinforce like comptech about 1000-1200

4. cryo and do a puddy rearend around 2000

5. do a inline setup About 4000

Puddy and I work together on these rearends.

PM him we have plenty in stockb at different levels.

 

OEM/COMPTECH/PUDDYMOD

PuddyMod is the way to go...Look at the difference, notice how the Comptech has a gap? this could still cause diff failure, which makes the reenforcement not as effective as the puddymod