what oil goes in the 6 speed I have an 02 6 speed 7.3 and a 08 6 speed 6.4
Incorrect. The ZF6 Transmissions (at least in the 99-02) take synthetic ATF, not gear oil. Although I read somewhere that the later ZF6's (08-10) use a different lubricating oil.When you say 6 speed, and 7.3 -- Are you referring to the ZF manual trans?? If so, that would need Gear Oil, and not ATF.
ATF throughout the ZF lineage 5 or 6spd, I think it was 08 or so that they started specifying the use of Synthetic and/or regular Merc-V (synthetic for diesel, reg merc v for gasser), but I dont ever recall GL4 or any other type of gear lube. The ZF's have little needle bearings that wont lube well with heavy oil.Nope. It's ATF (for the 02)
gear lube for the 08 (GL4)