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 your owner manual.

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 your owner manual.

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" in your owner manual.

Hydraulic Brake System

Delco Supreme 11® Brake Fluid or equivalent DOT-3 Brake Fluid.

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. 1051344) or NLGI #3 consistency.

Power Steering System

DEXRON®-VI Automatic Transmission Fluid.

Manual Transmission

Synthetic Manual Transmission Fluid (GM Part No. 88861952).

Automatic Transmission

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

Key Lock Cylinders

Multi-Purpose Lubricant, Superlube (GM Part No. 12346241).

Chassis Lubrication

Chassis Lubricant (GM Part No. 12377985) 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. 1051344).

Front Wheel Bearings with Oil Filled Hubs

SAE 75W-90 Synthetic Axle Lubricant for Medium Duty Trucks (GM Part No. 89021675).

Transfer Case (Four-Wheel Drive)

Manual Transmission Fluid (GM Part No. 88861800).

Front Axle (Four-Wheel Drive)

SAE 75W-90 Synthetic Axle Lubricant for Medium Duty Trucks (GM Part No. 89021675).

Rear Axle and Rear Hubs

SAE 75W-90 Synthetic Axle Lubricant for Medium Duty Trucks (GM Part No. 89021675).

Rear Axle Shift Motor Lubricant

Refrigerant Oil (GM Part No. 5416939).

Propshafts and Splines

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

Cab -- Door Hinges and Latches

Multi-Purpose Lubricant, Superlube (GM Part No. 12346241).

Weatherstrip Conditioning

Weatherstrip Lubricant (GM Part No. 3634770) or Dielectric Silicone Grease (GM Part No. 12345579).

Weatherstrip Squeaks

Synthetic Grease with Teflon, Superlube (GM Part No. 12371287).