Rear end noise, anybody know what this is?

nehuge wrote:
While going down the road, anywhere from 40 to 70 mph there is a loud humming noise from above the rear axle. It sounds as if I have an F150 with humongous monster mud tires on it. It's that same sound when you hear one of those big knobby tire guys going down the freeway.

Any ideas? If I let off the gas it quiets down, but holding it at speed or accelerating is when it does it.

I thought tires, but then though my other Class A with dually tires on the back didn't make that noise. Tires are brand new, and it did this sound before and after new tires anyway.

It's a Ford F53 Chassis, 1995, 35 footer. I have not checked differential fluid yet.

It sounds to me like your ring, and pinion are worn on the "drive" side, as it stops when you let off. And as long as it is pulling or holding speed it roars. In other words, when the "drive" side is working. It makes noise.

Easy fix really. New ring, and pinion. Less expensive than you think