Compatible 75w-90 differential oil?

[crispyboy]

My local autoparts house carries Mobil 1 and Valvoline Synpower 75w-90 weight synthetic gear oil. Are these equivalent to use in the front and rear 2500 American Axle differentials?

 

[jelag]

I looked up the spec information in the service manual I have for my truck and looked for that compliance on the label of the oil that I purchased... Each time I've gone back to purchase more... I buy the same brand. .

I would think that both brands you mentioned would comply, what do their labels say...

 

[crispyboy]

Yep - did some more research and both are API GL5 rated which is what is needed.

I probably thought too much about this and noticed the spec on an old Mopar branded 75w-90 container was MS-9763. I believe this spec is for the 1/2 ton axles. Neither brand mentions meeting this specification.

 

[BLNRAY]

i sure hope mobil 1 is ok,hate to find out 392,000mi later i am using the wrong oil

 

[Mark31]

i sure hope mobil 1 is ok,hate to find out 392,000mi later i am using the wrong oil

Ain't nothin like a little tongue-in-cheek!