I have the Nismo LSD and am getting ready to change the fluid because i dont know when the last time it was changed but i have put about 7000 miles on it since i bought the car. anyhow it does it's normal sounds when turning in a parking lot but just yesterday while driving in a straight line i started noticing a cunking, it sounded as if the diff was loose and kinda just shifting slightly and making a little clunk sound. i have never heard this in a straight line before. it is only while the throttle is applied. could this be just because the fluid os old?? i hope nothing got messed up. i noticed it after i was on the highway probably going a little to fast when i hit a slight dip in the asphalt and it threw the car almost sideways i corrected it ok and everything but when it hit and i straightened out it was very violent movements, could that have done some thing to the rear??

 

How many miles on the vehicle, total?

 

14k

 

I say change the fluid and see how it acts. If it is still making noises, you may need to take the rear end out and apart to inspect it.