Originally Posted by todthedod

I know this post is a couple months old, but I have a noise coming from the rear of my car. It's hard to describe the sound, but imagine you have a flat-spotted tire. It sounds like that but the frequency is shorter than the circumference of the tire. So with one revolution of the tire, I would hear the woompwoomp sound maybe 2x. (estimate) . To me it sounds like it's coming more from the right rear so I did change the right rear wheel bearing but it's still there. It's gradually getting louder and louder. it's been doing it awhile so I figured while I'm not driving it in the winter, I'll try to diagnose.

Just want to see what are the possiblities so I can do a visual inspection. I know the lsd is probably the culprit but don't want to order one unless I'm sure. What else should I check back there? Already changed the diff oil and it didn't change the sound at all.

Originally Posted by PARADOX_sf

Lift the car, put it in dyno mode and with tires in the air start shifting gears and accelerating. If there is a sound from the differential may be the diff bearings are bad. Change the diff oil and check for metal particles in it. After 1000miles change it again. If there are metallic particle like in metallic paint the bearings are bad 100%. If not the problem could be caused by tires.
Is the sound appears then slightly accelerate or deaccelerate?

Originally Posted by todthedod

It makes the noise when there's accel/and decel. I can lightly apply a tiny bit of throttle so it's kind of a neutral situation and there's no noise or at least significantly less noise. When it first started I thought it was the right rear wheel bearing as the sound seems to be more on the right side unless it's some kind of auditory illusion. The wheel bearing change didn't help. I've put new tires on but he noise is still there. I did change fluid when the noise first started and I don't remember any metal in it. I still have it in a container so can check this weekend. I'm guessing it's diff bearings but I'll get it up in the air this weekend. I'm clueless on diffs. If it's the bearings can you just change the diff bearings or do I need a new diff assembly like a wavetrac or something? Thanks for the help!