Recommended Fluid

All "S" series trucks, 4-speed manual transmission and the New Process 833 4-Speed Overdrive transmission use Dexron II automatic transmission fluid.

Isuzu 69.5 MM 5-speed transmission and all 5-speed transaxles use 5W-30 engine oil rated SF or equivalent.

All other transmissions use 80W or 80W-90 GL-5 multipurpose gear lubricant or equivalent.