Ok, I've noticed a something that has just started happening lately. When my car sits for a bit, it makes a grinding noise like metal on metal from the rear. Either forward or reverse. And it only makes the noise for about a 100 feet. It does it with the motion of the rear wheels. For example, the wheels turn 75% and then it grinds, another 75%, then it grinds , etc, etc. Then it stops. It's has me baffled. I don't know if it matters, but the guy who had the car before me put a spool in the posi so she is locked tight. Any ideas?

 

A spool permanently locks both axle shafts together so that both rear tires will always turn at the same speed. .... A spool is for going in a straight line, not for daily driving.....

 

Yeah I know that, it chews through tires pretty fast. Do you think that has anything to do with the noise thats developed?

 

Oh and btw, I know 4 people who drive their vehicles daily with spools (one is a 4th gen camaro and he is going on 6 years). Not trying to be a smartass, just saying

 

Have you changed the oil back there lately? I know the regular limited slip hub needs the special GM limited slip oil or else it makes all kinds of grinding noise.

Hal

 

It's not the factory rear end but I should probably change it anyways. Cheap insurance. I'll let ya know if that quiets it down. Thanks man.

 

Does "sits for a bit" mean long enough for the brake rotors to start to get a surface coat of rust?

 

I suppose I should have clarified what I meant by that. It makes the noise if it sits overnight for example. I'm gonna tear the rear apart tonight or tomorrow and I'll let you know what I find.

 

One of the bushings on the control arm had shifted causing it to rub. Put a new bushing in and noise went away.