any one know of reason for a low frequency hum and vibration that seems to be coming from the rear of my 93 z28 automatic? It is noticeable when I roll from a startup or come to a slow rolling stop. Once I get going at normal speeds I don't hear the noise. car has 98,000. miles of easy driving onit and runs great. The front hubs were replaced and that did not fix the noise. I'm now thinking it is one or both of the rear wheel bearings and hoping it is not the positraction differential. The rear end seems quiet and does not lock the tires when going around tight turns. any ideas are helpfull.

 

I heard a humming / rattling sound... then a few miles later, my rear end grenaded itself...

 

I sure hope that doesn't happen, but one way or another I'll get to the problem and fix it. The rear wheel bearings are being changed and I will report back here with the results.

 

well i'll tell you what it is not. neither the front wheels bearings or the rear wheel bearings. both were changed and problem still exists. how much does a new or rebuilt differential assembly cost?

 

After getting back the car form the mechanic who could not fix the problem,
I decided to rotate the tires just to make sure that was not the problem. Well you guessed it, a bad tire was the problem. Now that they are rotated there is no more low speed rumble or vibration.