should I believe haynes?

[brent]

Advises 75W-90 for all these things: T-Case/Diff/Manual Trans. Seems odd.
Anyway--both Checker and Autozone out of above so I bought a gallon of 80W-90 'cause I'm doing T-Case work in the AM (lube shifter rods) and I might as well get the tranny while I'm at it.
Is the 80 going to make a difference since the 70 was unavailable?
Thanks, Brent

[joe]

80w-90 is what you should be using.

[AJ Johnson]

use it.. the difference will be absolutely negligible in your application.

[gsmikie]

do it ............do it .............come on do it