I added some of this to my rear diff and it has helped alot to my surprise with the noise! It said it needs 20 miles to mix in so I guess it will get quieter as I have only driven it about 2 miles.
Also when I changed my leaking seal I greased the axle end and bearing really heavily. When that grease finally made its way into the gear oil that quieted the noise some. I guess it thickened the 75w140 more. I will try this next time as it is thicker and I think will work better.
