Better safe than sorry. The fluid specifications list GL-4 for the xfer box and GL-5 for the diffs, no 'or' notes that I've seen. Since the 4wd is shift on the fly, up to 65 mph, there must be some sort of synchronization going on. It's true that GL-5 is a better extreme pressure gear lube, as long as you have only steel components.

My main thrust was dissemination of information, and to warn people about the lubes that say they meet both specs, they do as far as extreme pressure goes, but are not safe for yellow metal.

1995 SR, dark blue, cloth seats, flare and cladding delete, upcoming sunroof delete,10 Guage custom skid plates, ham radio