advanced gear oil ?

[hiltu]

I purchased two built diffs from MC one with a grizzly and the other with an ARB. Bought some gear oil, got it home and saw it was GL-5. I've heard bad things about GL-5 before because of the difference in additives over GL-4. My concerning components are the lockers and oil seals. Is the GL-5 oil okay to use? thanks

[emsvitil]

Differentials need GL-5.   Some also need and additional additive.

Transmissions, tranfer cases will use GL-4.   (or a dual-rated GL-4/5 gear oil).    Some GL-5 gear oil additives will have an effect on the bronze synchros,  thus a gear oil rated only GL-5 shouldn't be used unless the manufacturer rates their tranny to use GL-5.

[hiltu]

thanks, that was somewhere along the lines of what i heard

[PhantomD aka Zach]

Is there any issue with using GL-4 in the diffs? I have to replace everything soon and was going to buy a 5 gal bucket.

EDIT, it seems to be difficult to get gl-4 in anything but expensive quarts.

-Zach