GMC Sierra 2018 Owner's Manual page 442

Usage
Front Axle Four-Wheel Drive
Hydraulic Brake System
Hydraulic Power Steering System
(2500/3500 Series Only)
Key Lock Cylinders, Hood Hinges,
Body Door Hinge Pins, Tailgate
Hinge and Linkage, Fuel Door Hinge,
Tailgate Handle Pivot Points, Hinges,
Latch Bolt, and Linkage
Rear Axle (1500 Series)
Rear Axle (2500/3500 Series)
Transfer Case (Four-Wheel Drive)
Weatherstrip Conditioning
Weatherstrip Squeaks
Windshield Washer
SAE 75W-90 Synthetic Axle Lubricant (GM Part No. 88900401, in
Canada 89021678).
DOT 3 Hydraulic Brake Fluid (GM Part No. 19353126, in
Canada 19299819).
GM Power Steering Fluid (GM Part No. 19329450, in Canada 19329451).
Multi-Purpose Lubricant, Superlube (GM Part No. 12346241, in
Canada 10953474).
SAE 75W-85 Synthetic Axle Lubricant (GM Part No. 19300457, in
Canada 19300458).
SAE 75W-90 Synthetic Axle Lubricant (GM Part No. 88900401, in
Canada 89021678).
DEXRON-VI Automatic Transmission Fluid.
Weatherstrip Lubricant (GM Part No. 3634770, in Canada 10953518) or
Dielectric Silicone Grease (GM Part No. 12345579, in Canada 10953481).
Synthetic Grease with Teflon, Superlube (GM Part No. 12371287, in
Canada 10953437).
Automotive windshield washer fluid that meets regional freeze protection
requirements.
Service and Maintenance
Fluid/Lubricant
441