2001 GMC Sierra 1500 Pickup Owner's Manual - Page 445

Weatherstrip Lubrication Silicone grease on weatherstrips will make them last longer, seal better, and not stick or squeak. Apply silicone grease with a clean cloth. During very cold, damp weather more frequent application may be required. See "Recommended Fluids and Lubricants" in the Index. Manual Transmission Check Check the transmission fluid level; add if needed. See "Manual Transmission Fluid" in the Index. Check for leaks. A fluid leak is the only reason for fluid loss. Have the system inspected and repaired if needed. Automatic Transmission Check Check the transmission fluid level; add if needed. See "Automatic Transmission Fluid" in the Index. A fluid loss may indicate a problem. Check the system and repair if needed. Hydraulic Clutch System Check Check the fluid level in the clutch reservoir. See "Hydraulic Clutch Fluid" in the Index. A fluid loss in this system could indicate a problem. Have the system inspected and repaired at once. At Least Once a Year Key Lock Cylinders Service Lubricate the key lock cylinders with the lubricant specified in Part D. Body Lubrication Service Lubricate all body door hinges, hood latch assembly, secondary latch, pivots, spring anchor, release pawl, tailgate hinge, tailgate linkage, tailgate handle pivot points, latch bolt, fuel door hinge, locks and folding seat hardware. Part D tells you what to use. More frequent lubrication may be required when exposed to a corrosive environment. 7-20