1998 GMC Sonoma Owner's Manual - Page 365

Wiper Blade Check Inspect wiper blades for wear or cracking. Replace blade inserts that appear worn or damaged or that streak or miss areas of the windshield. Also see "Wiper Blades, Cleaning" in the Index. At Least Four Times aYear Tailgate Lubrication Service Lubricate tailgate latch bolt, handle assembly pivot points, and hinges with lubricant recommended in Part D. Manual Transmission Check Check the transmission fluid level; if needed. See add "Manual Transmission" in the Index. Check for leaks. A fluid loss may indicate a problem.Have the system inspected and repaired if needed. At Least Once aYear Key Lock Cylinders Service Lubricate the key lock cylinders with the lubricant specified in Part D. Automatic Transmission Check Check the transmission fluid level; add needed. See if "Automatic Transmission"in the Index. A fluid loss may indicate a problem. Check the system and repairif needed. Body Lubrication Service Lubricate all body door and fuel door hinges, latches and locks including the glove box, console doorsand the body hood, and any moving seat hardware. Lubricate the hood safety lever pivot and prop rod pivot. Part D tells you what to use. More frequent lubrication may be required when exposed to a corrosive environment. 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. 7-43