MT-90 75W90 GL-4 Gear Oil. 75W90 GL-4 gear oil (similar to SAE 5W40/10W40 engine oil viscosity). SAE Viscosity Grade (Gear Oil): 75W90. SAE 75W90 SAE 90/80W90. API Service Class: GL 4. RED LINE MT-90 HIGH-PERFORMANCE GEAR OIL is a full-synthetic ester-based lubricant designed for use in manual transmissions and front-wheel-drive transaxles.
