I think my rear might be going. When I start to accelerate from a stop, my car makes a thump/grind sound from the rear and it feels like a skip in acceleration and it only lasts for less than a second. I tried accelerating from a stop but this time I pushed it a little harder and the sound got a little louder and more of a grinding sound and it lasted longer. It will also do it if I floor it from a 30-40 mph roll. Can someone tell me what might be wrong. BTW my car is a 98 SS with torsen rear, A4 with 3500 stall converter and 36000 miles, also my rear wheels are 17x11 with BFgoodrich drag radials.

Thanks

 

id say its probably starting to go. Turn off everything and roll the windows up on a quiet street. when you slow down for a stop sign listen for a "knocking" sound coming from the rear end. Thats a sure sign of the 10 bolt dyin...

 

A rearend typically will not making a grinding noise like your describe. It will whine but I won't rule out the rearend entirely. Check the rearend for leaks. The cover gasket and pinion seal being main culprits.

I would inspect the driveshaft and torque arm. A bad joint on a driveshaft may make this sound or a cracked torque arm.