If I remember correctly the 80/90 is recommended for the front diff only and the rear takes a 140 weight. The front diff is free rolling most of the time and doesn't work as hard or brake down and heat the fluid like the rear does. I'd certainly not recommend putting that light oil in the rear diff.
80w 90 gear oil
1986 to 1996 Manual Transmission and Transfer case use API GL4 or GL4 and GL5 80W90 or 75W90. Differentials use API GL-5 SAE 75W-90 or 80W-90 lubricant. Do not put a GL5 gear oil in the transmission unless it says GL4 and GL5. GL5 will attack the syncros.
Yes you can but the 80W will keep it a little cooler.
You are talking about a 1996 ISUZU HOMBRE 2.2L 4-cyl Engine Code 4The rear axle fluid that is recommended isDifferential, Front .....GL-5[5][6]All Temps......80W-90Differential, Rear .....GL-5[7][8]All Temps......80W-905. 80W-90 GL-5 is a synthetic lube; GM part no. 1052271.6. Do not add limited slip additive.7. 80W-90 GL-5 is a synthetic lube; GM part no. 1052271.8. Do not add limited slip additive.I recommend the following from Amsoil.SAE 80W-90 Synthetic Gear LubeSevere Gear 75W-90SAE 75W-90 Synthetic Gear LubeHope This Helps.
The 2001 Mercury Mountaineer Owner Guide shows : For the FRONT AXLE : ( Motorcraft SAE 80W-90 Premium Rear Axle Lubricant ) * 1.8 U.S. quarts
80w-90
80W-90 gear oil
75W-90 in the rear differential. 80W-90 in the front differential (4x4 models). This is according to the 2007 Chevrolet Suburban owner's manual.
Small plug on the front side of center part, on passenger side half way up, Use a 3/8 drive handle square socket, Crawl under in front right rear wheel.
According to the 2001 Ford Ranger Owner Guide : Front Axle Lubricant : ( Motorcraft SAE 80W-90 Premium Rear Axle Lubricant ) ( 1.7 liters / 3.6 U.S. pints )
80W-90 (GL-5) gear oil.
80W-90 GEAR OIL