alsatropine

iTrader: (2)

Hey guys. At about 50 mph I start getting a humming noise from my rear diff. Would this be a pinion bearing making this racket? Do I need to worry about it or leave it alone? I'm fixing to replace my pinion seal and output shaft seal and also have an axle seal I need to replace too, so if I needed to replace the pinion bearing, then I could knock out all of it at one time. What are your thoughts?

Martian

How're you sure it's your rear diff? When I got that hum it was my parking brake shoes hanging up on the drum because the scissor levers were rusted and wouldn't let the shoes back off when the brake was released.

alsatropine

iTrader: (2)

I checked my emergency brake a couple months ago when I upgraded my brakes. Everything was fine and not rusted...

str8flush

I have the same problem right now it only happens when I'm going from 50 to 60 mph on the throttle and if I'm coasting I don't hear it.

Z7What

The humming is a common issue on the 9.75" rearends. It's the gears NOT the bearings.

Wayne

Crazy4x4

I had the shop change out my all the bearings in the rear end early this summer. It helped with the hum, but it didn't cure it. It is mainly the gears.

Martian

Try removing it completely and drive it for a while. That won't cost you anything. If that doesn't help, you haven't lost anything.