My car has 75k miles on it. Occasionally when shifting at higher RPMs, I hear momentary grinding sound coming from what I think is the rear diff. It only lasts a fraction of a second and goes away. It's done it maybe 5 or 10 times since I bought the car. Last night when it was really cold out and I was backing out of my space at work and the rear end felt like I locked diff -- I swear I felt wheel hop for a second. I'm worried that this thing is trashed. Any ideas why that would be? The mileage is relatively low and the car is all original no mods except a cat back exhaust. Thanks!

 

When was the last time you changed the oil in it? How did it look?

 

I've only had the car for a few weeks so... never It's one of the things on my to-do list, with just about every other maintenence that can possibly be done ;P Is the LSD a sealed unit and can you use just regular gear oil in the diff? Thx!

 

It should be regular gear oil, i havent changed mine so you should check your manual for the proper spec. (its nice buying from guys that maintain their stuff and can actaully tell you the mileage that everything was last done)

If its never been done for the life of the car and some nasty looking metallic stuff comes out and you keep getting unusual symptoms once the oils changed then it may be time to buck up and replace it.

 

One of the fist things you shold do when getting a car used car is get all the fluids changed. this means coolant, engine oil, trans and rear dif oil. I would change the oil first and then see if the sound is still there, because if fresh oil fixes it, you are not out accouple grand for the diff and instiliation.

 

The diff is a Torsen (worm-gear type, not sealed) - uses regular GL-5 lube.

 

If you need to replace it, I have the OEM LSD with the ring & pinion for sale. It's in perfect working condition and has very low miles. PM me if you need the unit.