80w-90 fluid

[Hunter]

i have a 2006 tahoe changing my rear end fluid calls for 80w-90 fluid. Can I use GL-5 80w-90 axle gear oil ? It’s made by AC Delco. Thanks for the help
Also how do I know what size is my rear ? A lot of options on my tahoe.

 

[swathdiver]

Double check your information. It should be 75W90 synthetic. The current AC Delco part number is 10-4016 which includes the limited slip additive.

 

[HiHoeSilver]

Here are the manual specs from 2006.



There are only two rear end sizes. 8.5 and 9.5
Count the bolts. There will be either 10 or 14.
Your Tahoe came stock 8.5, 10 bolt.
If you mean ratio, then check the glove box for an RPO code. You most likely will see GU6, which is 3.42.

 

[Chubbs]

Can I use GL-5 80w-90 axle gear oil ?
YES, BUT IT'S NOT THE EXACT SPEC.
NO, IF YOU HAVE LIMITED SLIP (RPO g86?) WHICH REQUIRES MODIFIERS IN THE OIL


Also how do I know what size is my rear ?

COUNT THE NUMBER OF BOLTS IN THE DIFF COVER OR INSPECT THE RPO CODES LISTED IN THE PASSENGER SIDE GLOVE BOX.