Hey guys i had a big spin at the track last week and ever since there is a humming noise from inside the car. if i jack the car up, put it in gear and get it up to about 30 mph i hear alot of noise from under the car, but i cant figure out where its coming from because the noise travels through the whole drive train, but im pretty sure its the diff.

Anyways, onto my question about the diff and LSD. Im pretty sure the sound is coming from the diff but not 100 percent sure. So if i put the car in the air, and just spin one wheel by hand, what should the other wheel do. From my understanding with an LSD the other wheel should spin the same direction. Am i correct?

When i spin either of the wheels, nothing happens on the other wheel, it just sits still. Is my lsd blown? Or have i overlooked something?

Thanks in advance guys

 

Additional information for anyone who can help with my problem.

- Sound started after the spin, where i accidently went from 2nd to 1st at 60 mph during a corner.
- Car only makes sound when its under load. Its silent in neutral, its silent in gear when there is no throttle application.
- There is no vibration, the car is smooth.
- To best explain the sound it is a deep "wa wa wa wa" sound

 

With the car off, and IN GEAR:

Turn a rear wheel. The OTHER rear wheel will turn in the opposite direction.

 

Thanks. Just tried that and indeed with the car in gear the wheel spins the opposite direction

 

You can't really break the limited slip action of the diff without breaking the whole diff. It's not a posi traction diff or VLSD or anything...so it has no clutch packs.

The diff sends torque to the slipping wheel via a worm gear. So you never "wear out" the limited slip ability of the diff. It's either broken or it's good as far as being a LSD is concerned.

The humming could be coming from a bearing or something in the diff.