Grinding noise coming from what I believe is the rear end when driving between idle and 30 MPH.

Jacob McDowell · March 2, 2022

For the past few months I've been having an issue with a grinding noise when driving between idle speeds and about 30 MPH. It seems like it is coming from the rear end but I can't really be sure. I just recently changed my rear diff fluid. There is a lot of dust accumulated when the rear axle meets the axle tube (if that's what it's called) behind the brake dust shield. I haven't checked to see if there is any play yet in the rear axles to check bearings but I'm just at a loss with what it could be. The truck has 67,000 miles.

Edited March 2, 2022 by Jacob McDowell

CamGTP · March 2, 2022

Is the area with the build up also wet or damp looking?

A leaking/seeping axle seal will cause everything to stick to it.

If the sound is coming from the rear end like that you may be at the point of taking things apart to look for possible damage. That would mean removing the diff cover to look at the gears and check for metal in the bottom. While also remove the brakes/calipers and pulling the axle shafts out. That way you can inspect the axle bearings that the axle shafts ride on. I've seen those go bad and it can cause some serious damage.

Jacob McDowell · March 3, 2022

33 minutes ago, CamGTP said:

Is the area with the build up also wet or damp looking?

A leaking/seeping axle seal will cause everything to stick to it.

If the sound is coming from the rear end like that you may be at the point of taking things apart to look for possible damage. That would mean removing the diff cover to look at the gears and check for metal in the bottom. While also remove the brakes/calipers and pulling the axle shafts out. That way you can inspect the axle bearings that the axle shafts ride on. I've seen those go bad and it can cause some serious damage.

The area has a bunch of dirt stuck to it. I figure I can probably do it myself if it's not too difficult. There wasn't really any metal at the bottom of the diff however when I spin the wheels I can heat a clicking inside of the diff. When I had it open it was a piece at the top of the diff I think the locker maybe? I'm not sure if it's supposed to make a clicking sound or not.

JimCost2014 · March 3, 2022

20 hours ago, Jacob McDowell said:

The area has a bunch of dirt stuck to it. I figure I can probably do it myself if it's not too difficult. There wasn't really any metal at the bottom of the diff however when I spin the wheels I can heat a clicking inside of the diff. When I had it open it was a piece at the top of the diff I think the locker maybe? I'm not sure if it's supposed to make a clicking sound or not.

This is the inside of a G80 locker rear end in GM trucks.