I've got an '02 SS and recently I noticed when you jump on it in first, second or third gear you hear a popping/grinding noise coming from the back...my guess is the differential. It's the worst in 1st, not so bad in second, and hardly noticable in 3rd. This noise ONLY happens when you jump on it though and doesn't last throughout the entire RPM range on the gear in 2nd or 3rd...in 3rd it's barely noticeable and only lasts a few hundred RPM. If you drive and accelerate normal you never hear anything and don't hear anything in 4th-6th gears regardless. The car has 48k miles on it.

Thoughts? I've never messed with a differential, changing the oil in it, is it as simple as taking the cover off, cleaning it out, putting new oil in and closing it up? does this sound indicative of a differential going out or a bad gear?

thanks,
John

 

When you jump on it is a good discription of abuse. My guess would be the LSD is going out.

 

First thing I would check is your trans mount. The torque arm from the rearend mounts to the tail of the trans. If the mount is bad, the lifting force from the torque arm will raise the tail of the trans. The trans can then smack the tunnel making a "bang" noise when you accelerate. You could also be tweaking the front pinion/rear u-joint creating a bind, or the abnormal force could be giving you a momentary bad mesh in your ring & pinion gears.

 

I'll check the mounts. That sounds more like it could be the noise. At first, I thought it was an exhaust pipe vibrating against the axl but this sounds more solid than that.

 

I'm going to agree with Camaro 69 here. These cars have a bad tendency of breaking the stock trans mounts. Does the noise sound like it's coming from the rear end or more towards the center console area? Can you feel any "bump" when the noise occurs?

 

The noise is definitely center on the car (side to side) but I can't say off-hand front to back where it was...I'll take a peak though and see what I can find.
When I felt it the first time there was a definite "bump" or bang noise followed by a quieter noise but seemed very much a vibration. The instant I let off the gas or eased off it, the noise went away. It's only there during that fast acceleration time that you hear it. Under normal driving you wouldn't have a clue anything was going on.

 

When you jump on the throttle, if the sound you hear is like a thump/bang/thud, then I would say trans mount. Especially if you like standing on the gas pedal a lot.
Running it hard can break it easy!

 

I agree! More than likely it is a mount. I have a 95 z-28 and I have had to replace mine NUMEROUS times. It happens.