MatthewJon

2007 OBS Sierra Classic 1500
5.3 motor.

The rear is a 10 bolt. Im asking because I want to change out the fluid, just dont know how much to buy.

Thank you.

ndependent

Are you talking about the rear end? If so its going to take almose 3 of the rear end containers. Not sure how big they are . I think they are quart size.

budhayes3

iTrader: (19)

Do you have the G80? The factory calls for synthetic 75w-90, as mentioned get 3 containers of it and you'll use about 2.5 to 2.75 of them IIRC

MatthewJon

how do i know if it is a g80?

viciousknid

iTrader: (8)

Look in the glove box for code G80

MatthewJon

Thanks, it is a G80 rear, so 5.5 pints.

Is the front diff an 8.25" or 9.25" ring and gear? What codes are they?

Thanks for the info, I appreciate it!

viciousknid

iTrader: (8)

the code G80 means your rear diff has an Eaton "G80" Limited Slip Differential which will explode immediately if you use the wrong fluid. It's not very strong.
If your not buying a ring and gear it doesn't really matter what size the front is. You just need to make sure you have the proper fluid.

Run Synthetic in the rear since it has a g80 and run normal 80/85/90 in the front is what I'd do.

AKlowriderZ71

iTrader: (22)

^^^hilarious^^^

You should use synthetic in the rear diff, no matter what. Most need about 2.6 qts. GM actually recommends synthetic in the front differential if you are in a cold climate. It will use just under 2 qts.

If you are not in a cold climate, you could use any GL-5 rated 80w-90 gear oil in the front diff.

MatthewJon

Did the front, last fall, now im going to do the rear...finally

anyone know what the rear diff cover torque specs?

thanks

MatthewJon

is hand tight plus a 1/4 turn good enough?