to be helpfull, trans(aw4) is dexII/atf3 transfercase is also dexII/aft3 diff oil, gear oil, GL-5, thickness is a prefferance, as is motor oil
CORRECTIONS:
AW4 takes Dex II/IIE/III/VI and
not ATF +3/+4. Friction modifiers are wrong in +3/+4, and use can (and usually does) lead to clutch chatter and slip.
The tcase (NP231/NP242) can take Dex or +3/+4 - no clutches. The ATF is used as a simple lubricant, and is circulated by a small gearotor pump.
Manual transmissions: The BA-10/5 (1987-1988.0) takes GL-5 just fine, but the AX-15 (1988.5-1999) takes GL-3 (bronze synchronisers. GL-5 may be used if it specifically sez it is "Safe for use with yellow metals." The NV3550 (2000-2001 may take its own fluid.)
Axles: GL-5, 80W-90 for standard service and 75W140 (rear) for towing/heavy duty. Add 2oz of friction modifier if you have a clutch-based limited slip.
Engine:
Do not use API SM "Energy Saving" engine oil! Use of SM can lead to camshaft failure in flat tappet engines like ours. The API rating will be in a rondel on the back lable, but if you see the "Energy Saving" sunburst on the front label, drop the bottle and find oil that doesn't have it. If you can't, stop by the GM dealership and stock up on EOS - add one bottle at
every oil change.
Capacities and recommendations (per FSM/TSM) are listed on my site in the Tech Archives - check them out!