killagt

iTrader: (3)

Beside dealer ? I have problem with dealer peoples, few month ago, so I promise myself I never step into GM dealer for part again. Just wonder where else online that carry that stuff ?

GM rear differential additive. GM Part number 1052358

BTW any one here running mobil 1 on their rear ? does it require additive if you go syntec ? thanks

redbird555

iTrader: (14)

Advance and autozone sells it. Ive used it for the last 2 changes on a couple of cars and its fine. Remember though you only need the additive if you have the clutch type auburn posi.

xbcrguy182x

I believe WS6Store.com carries it.

7camaro7

iTrader: (15)

I don't think my car has an auburn diff, but I know that if I do not have that additive in it, it will make lots of noises... I figure if I had that kind of diff it would be listed in my pass side door under my options, but it is not. It is required if you have lsd period. That's what the owner's manual says.

op, I'd just find a better dealer.

hitmanws6

iTrader: (20)

i know some fluid has the additive in it already. the stuff we use at work does

7camaro7

iTrader: (15)

yea last time I believed that is how I learned! I went to valvoline in chattanooga and had them to change my diff fluid. It was supposed to have the additive in it. I drove to chicago and when I was making 90 degree turns I heard grinding. later on found out I needed the gm additive. I put the additive in and the grinding hasn't been back since.