Ok so the car only has 40k on it, but it was raced hard for 30k. I could tell by how destroyed the t56 was, the shop even said the wear on the trans was worse than the t56 they just took off a car w/ 150k. So I got that rebuilt, new everything (clutch,pp,fw etc..).

Recently I capped my cutout so I could hear the many problems my car has, and one of them that I noticed right off that bat is a noise coming from the rear, I can only hear it at low speed (less than 5 mph) and it only happens when say you decelerate from 50-0 pretty quick then around 10 mpg take a sharp right or left. The odd part is it won't do it when the car is cold, only after you have driven it for a while (30 minutes) but once it gets fully warmed up and has been driven a lot when doing even sharp turns in a parking lot you can hear the noise, but only sharp turns.

The noise sounds something like an exhaust pipe hitting back and forth between the trans tunnel but It's not even close. You can't feel anything inside the car only hear the noise.

BTW: I changed the rear end fluid and put GM additive in about 10k ago. The rear has always had oil sepage around both sides where the axel covers come out, seems to be more on one side this time, and none on the other. (Not necessarily a leak but maby the vents on the top of the covers)

The reason why I suspected the rear end was because of how torn the trans was I assume the rear end has taken a lot of abuse as well.

The car has a leaky headgasket, wp, no a/c and I've throw a lot of money at it already so if it is the rear end I'm prolly gona sell it. That's why I am curious if this is an early warning sign to posi/rear-end failure, if not what are some signs?

Another thing which may or may not be related, when I let the clutch up quick on a slow shift I get a clunk from the back of the car.

 

I am having the same type of problems. Hope you get a response.

 

or not...