GL-5 LIMITED SLIP GEAR OIL Superior 75W-90 / 80W-90 / 85W-140 with XPL+ Technology The API GL-5 Limited Slip Gear Oil is a high performance extreme pressure automotive gear lubricant for use in passenger car and truck axles with hypoid gear sets. It is designed to the meet the most stringest requirements of severe gear oil tests. It reduces oxidative sludge and varnish, dramatically reduces wear, prevents scoring, and protects against metal fatigue.