drain the rear differential fluid, ive replaced many rear diffs for noise concern. if the fluid looks like glitter, that is your problem.

 

I will check that today. I change out the diff fluids every year. This past summer I decided to use Synthetic instead of the SAE90. Is there any additive I could use to help it along?
Update: Drained the rear diff and it was clear. No metallic in oil, only slight amount of sludge on the magnet. I filled with 80W-90, and a bottle of friction modifier. I also had the rear up 8" for the fill. Still making noise.

 

What abouy the front diff, how did that fluid look?

 

Did the front diff today and its all clear. No metallic in fluid and the magnet had very little.
Tomorrow I will drain the transfer case fluid and check.

 

I took it to the local transmission shop today, and they put it on the hoist and ran it. They diagnosed both front wheel bearing the driver side being the worst.
I had the driver side done less than two years ago.
Looks like I need to get a third opinion, as the first mechanic said the bearing where good. If it is the front WB any particular brand I should go with?

 

I prefer made in the USA bearings but many companies farm them over seas.

 

NTN, SKF, or Timken are all good makes.