Gears & Axles - 2002 SS Rear End Noise (?)

My 30k original mile `02 6-speed SS has recently developed what I would best describe as a dull "thud" type of noise that seems to be coming from either the rear end or the rear brakes (the brakes - probably less likely) while braking and/or down shifting while letting out the clutch as the car slows to a stop. This usually happens at about 10 mph or less. I first noticed this while backing out of the driveway in reverse (down a hill) before shifting into 1st, but it typically happens at all times now. The more abrupt the braking/clutch release, the more pronounced the "thud". My initial thought was the rear U-Joint, and it might be, but it seems like I should get better than 30k miles out of a U-Joint. One way or the other, the main trigger that causes this seems to be relieving any load on the drivetrain, whether it's through braking or releasing the clutch or a combination of both. This car is fully loaded, with all SLP options and it's original LS1. It currently has 2002 Z06 wheels with Nexan 2000 275-40-17's. Any thoughts or inputs on this would be greatly appreciated.

Thanks,

Bigblox

I'd look for a broken transmission mount, as it makes this exact sound when it is broken. Noises under the car can be hard to detect exactly where they're coming from. The factory torque arm is mounted to the transmission, which over time can cause the transmission mount to break. You may have to pry up on the transmission to have a broken mount show up. Bob

Check the rear sway bar bushings, check the torque ARM bolts.

U joint is going bad. Not a big deal.