Grinding noise FIXED!

[roperteacher]

About 3,000 miles ago I switched to AMSOIL series 2000 75-90 in my rear diff. Shortly after I began to get a grind from the rear while pulling a load. Around corners and such. It sounded like a rear diff that needed the friction modifier. I switched to Valvoline and the noise is 100% gone!!! Towing etc. I loved the AMSOIL, but dealer said that the friction modifier that is already in it probably cause the rear to slip, etc. It sure quieted down the howl, but just didn't work in my particular truck. Great fluid though!!

 

[jsimpson]

Had the same problem in my Vette. Switched from regular Amsoil to racing Amsoila and problem is permanently gone.

 

[Jengle]

That's funny. I changed out my diff oil at 17k for Amsoil 75-W90, series 2000 and my diff quieted down. I also have no problems with the LSD working. Now have 25k on the truck and all is fine. I switched all the fluids except the engine oil to Amsoil, xfer case, transmission, front and rear diffs. Keep posting your results, maybe we can find a trend here.

 

[roperteacher]

I was absolutely pleased with how the AMSOIL quieted my rear diff. It would howl like the dickens between 65-70 MPH. Was already rebuilt once at 2200 miles. The AMSOIL sure got rid of it... But shortly after putting it in, I began to grind on corners so I switched it out after only 3,000 miles just to test the theory. Diff seems to be staying quiet, but the grind is completely gone now. Maybe I can go half and half next time?