Dump the oil then use some brake cleaner just to get some of the black foam out then use the cheapest oil you can find run it a month or two then dump again use either the same cheap stuff or a quality oil.

You may be surprised what you get out after the first dump

I have a suggestion on what that noise may be????

You have a bad Hub on the front I had the same thing happen sounded like the rear end was grinding it always sounded like the noise was coming from my rear.

But it was a bad Hub

 

I just ran the VIN on the Dodge.com site.

My truck has a "Corporate" 8.25" rear end with 3.55 gears.

Still don't know if it has Traction-Loc or not. How can I check if it does or not ?

There is no ID tag on it what-so-ever.

 

The guys at the shop didn't look at that? Or, did they just look in the hole, and not pull the cover?

Get a build sheet. You may just need to add friction modifier to the fluid.

 

Roger that.

I need to know what type/viscosity fluid to put back in it. Not sure if it has a LSD or not. Yet.....

Roger that on the front wheel hub. It checks out A-Ok.

 

Yes, they sucked some fluid out into a clear container/tube to show me the foam. He did it through the hole, did not remove the cover.

I just requested the Build sheet via link in that thread.

Still need to know if mine is LSD or not and what fluid to put in it.

 

One way to tell is pull the cover if it looks like my Diff its not an LSD

 

If not an LSD than its 75W-90 GL-5 gear oil check for local weather what may be recommended but I still think its going to be 75W-90 GL-5.

 

Jack the truck up, keep trans in park. Spin one rear wheel. If it's locked, it's LSD. If it rolls and the other tire spins the other direction, it's an open carrier.

 

That's what I thought. I'll check that.

 

It would say "anti-spin" if you had the limited slip.

Post your build sheet and we'll decode it.