GMC 2002 Yukon Denali Owner's Manual page 387

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.
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.
7-18
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 hood latch assembly, secondary latch, pivots,
spring anchor, release pawl, door hinges, liftgate hinge,
liftgate linkage, liftgate 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.