High pitch noise from rear of car.

Since changing my differential oil, I've noticed that there has been a high pitch noise coming from the rear of the car. At first, the car was also very underpowered but I later found out that the handbrake return mech had seized.

I replaced my diff oil with Red-Line 75W90, is it the right choice and is it this that is causing the noise or has something in the brake area warped under the heat caused by driving with the handbrake on?.

When driving, the noise cannot be heard over the acceleration noise, but when in gear and not pressing the accelerator then it can be heard. It also seems to go away when i'm traving at speed in neutral.

Thanks in advance,

Coops

I would get the car up on a lift and have a good mechanic listen. Works better than playing guessing games. On the other hand you may find help at www.miataforum.com.

Arthur (remove .remove 4 email) 99 Miata user