rear diffential

[1234]

Getting a humming sound from the rear differential. Big problem...or simple service?

[JRL]

IF it's the diff, BIG problem
Perhaps a rear wheel bearing, more common

[sjonnie]

A rear diff going out of spec makes a noise usually only when you apply gas, that is, little or no noise when coasting, more noise when accelerating. A wheel bearing going out will make a noise that changes with speed independent of acceleration.

[Slowvo]

How about when you off the gas and coasting. I get a humming/rattling sound from the rear end when I let up off the gas. The noise seems to go away when I get back on the gas.

Does anyone know if this is a bearingr or the differential?

[Chilled Man]

I have a spare one I will never be using LOL

[skibo]

How about when you off the gas and coasting. I get a humming/rattling sound from the rear end when I let up off the gas. The noise seems to go away when I get back on the gas.

Does anyone know if this is a bearingr or the differential?

Totally different beast, but when the rear differential of my '75 Chevy went bad after 240,000 miles it had the exact same symptom. It was OK when the drive shaft was loaded in either 'direction' (either on the gas, or totally off the gas when the engine was doing some braking), but when the drive shaft was 'slack' it made a racket.

It got progressively worse over the course of a summer until a tooth on the ring gear broke off.

[Slowvo]

I have a spare one I will never be using LOL

How much you selling it for?
I'm trying to confirm it this is the problem or if i need Bearings

[Allen]

Bearings will howl regardless of what you're doing. If the wheels are spinning, they'll be howling.