What oil should I use in ZF 6-speed and rearend?

[jon6.0]

What should I use and what weights. I bought a new truck today and it didn't come with a manual.

[ob_1jr]

Well, from my owner's manual, it states:

Manual transmission (6 speed) - TranSynd™ Synthetic Transmission
Fluid (GM Part No. U.S. 12378515, in Canada 88900701).

As far as the rear end: SAE 75W-90 Synthetic Axle Lubricant (GM Part No. U.S. 12378261, in Canada 10953455)meeting GM Specification 9986115.

I think the rear end fluid this lists is for the "grape Juice" and it is very expensive (like $25 or more a quart...rear end takes about 4). I have been running mobil 1 synthetic gear lube. as long as it meets the GL5 rating, you are good to go. No friction modifier needed either.

PM me your e-mail address and I can send you an electronic copy of the 3 manuals that came with mine.