The information there showing a 75W-90 GL-3 gear lube is correct. To that can be added 75W-90 GL-4 with the latest factory recommendation being a synthetic 10W-30 engine oil. Redline's MT-90 is a 75W-90 GL-4 which is just a better version of GL-3. A GL-5 75W-90 gear lube is NOT however an improved version of either and is not suitable for use in the AX-5 or AX-15 transmissions. There are a few synthetic GL-5 75W-90 that are ok for use but you have to read the label to make sure of that. If the synthetic GL-5 75W-90 indicates it is safe for "yellow" metals which includes brass which is what the transmission's synchronizers are made from, it is safe for use in the AX-5 and AX-15 transmission used through 1999.
Synthetic 10W-30 engine oil, which is roughly the same viscosity as a 75W-90 gear lube, was added to make it easier to find on the store shelves since GL-3 and GL-4 gear lubes are not stocked by many auto parts dealers.