1999 GMC Sonoma Owner's Manual - Page 337

yellowblue Long Trip/Highway Scheduled Maintenance The services shown in this schedule up to 100,000 miles (166 000 km) should be performed after 100,000 miles (166 000 km) at the same intervals. The services shown at 150,000 miles (240 000 km) should be performed at the same interval after 150,000 miles (240 000 km). See "Owner Checks and Services" and "Periodic Maintenance Inspections" following. # Lubricate the front suspension, ball joints, steering linkage, parking brake cable guides, propshaft splines, universal joints and brake pedal springs. + A good time to check your brakes is during tire rotation. See "Brake System Inspection" under "Periodic Maintenance Inspections" in Part C of this schedule. ** Drive axle service (see "Recommended Fluids and Lubricants" in the Index for proper lubricant to use): Footnotes [ The U.S. Environmental Protection Agency or the D Locking Differential -- Drain fluid and refill at first D California Air Resources Board has determined that the failure to perform this maintenance item will not nullify the emission warranty or limit recall liability prior to the completion of the vehicle's useful life. We, however, urge that all recommended maintenance services be performed at the indicated intervals and the maintenance be recorded. engine oil change. At subsequent oil changes, check fluid level and add fluid as needed. Standard Differential -- Check fluid level and add fluid as needed at every engine oil change. 7-29