Rear Axle/Diff Noise?

[tcp710]

I've finally started rolling my project car and as I drive I am getting a pulsing "whurr" that can be matched to wheel speed.

Before I tear the whole rear axle assembly and diff apart, I want to try pin point the problem. If it is the center section or the wheel bearings. While driving the car it is hard to tell which is making the noise.

Any suggestions on where to start? Ideally, I would tear it right down, and rebuild it all brakes included, but to replace gears, bearings, add a limited slip, etc. that starts adding up using all new parts.

Any thoughts on a starting point are appreciated.

 

[1970Duster]

It helps if you state which rearend you have/working on. 7.25, 8.25, 8.75, or Dana 60.

 

[oldkimmer]

...............whurring noise is usually pinion bearings..............kim...........

 

[tcp710]

8.75 rear end.

 

[TrailBeast]

...............whurring noise is usually pinion bearings..............kim...........

He said at wheel speed though, so lets assume that for now.
Put it up on blocks and pull the axles and run it. (is the noise still there?)
If it is, then it's the pinion or center section.(carrier bearings)
If the noise is gone then change the wheel/axle bearings.

 

[Supershafts]

You may be focusing on the wrong issue, diffs don't pulse