ArticGMC

I have done some searches on several boards and have seen different opinions on the use of synthetic oil in the rear end. I just had an eaton posi and and set of 3.73 gears installed in my 01 Sierra. The installer used royal purple syn oil with the posi additive. Should I change to dino oil when I change at 500 miles or is it ok to put in the same oil?

The company that I bought both from said to use synthetic. I have also read, on different forums, that two differnt people asked eaton employee's asked the same question and got a yes and a no.

Thanks for any input,
Larry

StevieZ

iTrader: (3)

Synthetic all the way! Cooler temps,less noise and more protection. Just make sure you use a shockproof synthetic . ie: Redline shockproof or RP.

SSCamaro99_3

iTrader: (1)

What about synthetic with the Auburn rear end. I heard you shouldn't do it.