I have had my differential rebuild about half a year ago. Before it was a constant loud whining sound comming from the differential. After the rebuild it when away as expected. Everything was replaced except the gears themselves. And the axle bearings were not replaced because I was told they still looked to be in good condition. But now suddenly there is a new noise from the rear. Sounds different than it did before I had the differential rebuild. When driving it would be louder at certain speeds like 25 mph was it’s worst point. You could feel it vibrate the truck. I put it on jack stand and spun the tires by hand and I could hear a sound coming from the axle or in the differential. The sound is constant. Sounds like a grinding sound. Any ideas what this may be? Is it possible it could be bad axle bearings or a problem with the differential?

 

If you are hearing it from the center, pull the cover, and have a look.

 

I was planning on calling the guy that rebuilt it. I Also noticed when you pull in the hubs they move out slightly and click. Is that anything to worry about or is a little bit of play in the axles normal? But if I i did remove the cover to take a look, what should I look for? Am I listening closer to see where exactly the noise is coming from or to look for something physically by testing things inside the differential?

 

A little bit of movement in/out of the axles is normal.

You are looking for something obvious, chipped teeth, crunchy parts in the bottom of the housing, metal shavings, things like that.