Engine Oil (Gasoline Engine)

Engine oil which meets GM Standard GM6094M and displays the American Petroleum Institute (API) Certified for Gasoline Engines starburst symbol. To determine the proper viscosity for your vehicle's engine, see "Engine Oil" in the Index.

Engine Oil (DURAMAX®/Isuzu Diesel Engines)

Engine oils with the letters CJ-4 are required for your vehicle. The CJ-4 designation can appear either alone or in combination with other American Petroleum Institute (API) designations, such as API CJ-4/SL. These letters show API levels of quality. To determine the preferred viscosity for your vehicle's diesel engine, see "Engine Oil" in the Index.

Engine Oil (Caterpillar® Diesel Engine)

See the Caterpillar® Operation & Maintenance Manual for engine oil recommendations.

Engine Coolant (Caterpillar® Diesel Engine)

See the Caterpillar® Operation & Maintenance Manual for engine coolant recommendations.

Engine Coolant (Gasoline Engine & DURAMAX®/Isuzu Diesel Engines)

50/50 mixture of clean, drinkable water and use only DEX-COOL® Coolant. See Engine Coolant.

Hydraulic Brake System

DOT 3 Hydraulic Brake Fluid (GM Part No. U.S. 12377967, in Canada 89021320).

Windshield Washer Solvent

Optikleen® Washer Solvent.

Clutch Bearing Lubricant

Clutch Bearing Lubricant (GM Part No. 12378484 or equivalent NLGI #3 consistency).

Exhaust Brake Ball Joint Cap Lubricant

High-Temperature Grease (GM Part No. U.S. 1051344, in Canada 903037) or NLGI #3 consistency.

Power Steering System

DEXRON®-VI Automatic Transmission Fluid.

Manual Transmission

Synthetic Manual Transmission Fluid (GM Part No. U.S. 88861952, in Canada 88861953).

Automatic Transmission

See the Allison Transmission® Operator's Manual for correct transmission fluid.

Key Lock Cylinders

Multi-Purpose Lubricant, Superlube (GM Part No. U.S. 12346241, in Canada 10953474).

Chassis Lubrication

Chassis Lubricant (GM Part No. U.S. 12377985, in Canada 88901242) or lubricant meeting requirements of NLGI #2, Category LB or GC-LB.

Front Wheel Bearings (Except Oil Filled Hubs)

Wheel bearing lubricant meeting requirements of NLGI #2, Category GC or GC-LB (GM Part No. U.S. 1051344, in Canada 993037).

Front Wheel Bearings with Oil Filled Hubs

SAE 75W-90 Synthetic Axle Lubricant for Medium Duty Trucks (GM Part No. U.S. 89021675, in Canada 10953512).

Transfer Case (Four-Wheel Drive)

Manual Transmission Fluid (GM Part No. U.S. 88861800, in Canada 88861801).

Front Axle (Four-Wheel Drive)

SAE 75W-90 Synthetic Axle Lubricant for Medium Duty Trucks (GM Part No. U.S. 89021675, in Canada 10953512).

Rear Axle and Rear Hubs

SAE 75W-90 Synthetic Axle Lubricant for Medium Duty Trucks (GM Part No. U.S. 89021675, in Canada 10953512).

Rear Axle Shift Motor Lubricant

Refrigerant Oil (GM Part No. U.S. 5416939, in Canada 10953496).

Propshafts and Splines

Wheel bearing lubricant meeting requirements of NLGI #2, Category GC or GC-LB (GM Part No. U.S. 1051344, in Canada 993037).

Cab -- Door Hinges and Latches

Multi-Purpose Lubricant, Superlube (GM Part No. U.S. 12346241, in Canada 10953474).

Weatherstrip Conditioning

Weatherstrip Lubricant (GM Part No. U.S. 3634770, in Canada 10953518) or Dielectric Silicone Grease (GM Part No. U.S. 12345579, in Canada 992887).

Weatherstrip Squeaks

Synthetic Grease with Teflon, Superlube (GM Part No. U.S. 12371287, in Canada 10953437).