Currie 9-Inch Racing Gear Oil

1 quart of non-synthetic Currie 85w-140, API GL-6 Racing Gear Oil.

9-Inch API GL-6 Requirement
Due to the high-offset hypoid design (very high shear) of the 9-inch ring and pinion gears, a severe duty petroleum-based gear oil with API GL-6 specification is mandatory. The use of synthetic or GL-5 specification gear oils will result in premature wear of the gears and excess heat buildup that will damage internal components, voiding the Currie Warranty.

Oil Capacities
The following are estimations of oil capacities for your new 9-inch and Currie^® axle assemblies. Extreme pinion angles, as well as aftermarket components (such as diff covers),  may drastically change the unit’s capacity.

Currie 9-inch ....................................3 qts.
Currie F9 3 or 3.25 in. tube.................4 qts.
Currie F9 3.5, 4 or 4.5 in. tube............5 qts.
Currie Independent Center .................2 qts.
Currie 44 front...................................1.5 qts.
Currie 44 rear....................................2 qts.
Currie 60 front...................................2.5 qts.
Currie 60 rear ...................................3.5 qts.
Currie 70 front...................................3 qts.
Currie 70 rear....................................3.5 qts.

If you have a clutch-type limited-slip differential, a friction modifier additive must be used in addition to this oil.

Link to Torque Specifications

ALTERNATIVE GEAR OILS THAT ARE PROVEN TO WORK IN 9-INCH REARENDS

Torco - RGO 85w-140
SWEPCO - 203 MolyXP Gear Lube 250w (Racing or extreme application)