1995 GMC Yukon Owner's Manual - Page 443

Maintenance Schedule I - Diesel Engines 50,000 Miles (80 000 km) Change engine oil and filter (or every 3 months, whichever occurs first). An Ernissior? C o m d Service. 0 Lubricate the front suspension, king pin bushings, steering linkage, transmission shift linkage, transfer case shift linkage, parking brake cable guides, rear driveline center splines, front axle propshaft splines, brake pedal springs and clutch pedal springs. Ball joints and king pin bushings should not be lubricated unless their temperature is I O " F (-12" C), or higher. When weather is cold, let the ball joints and king pin bushings warm up before lubrication or they could be damaged. Perform each of the listed lubrication service items at this mileage rs interval (or every I 2 months, whichever o c c ~ ~first). 0 Change automatic transmission fluid and filter if the vehicle is mainly driven under one or more of these conditions: In heavy city traffic where the outside temperature regularly reaches 90°F (32°C) or higher. In hilly or mountainous terrain. When doing frequent trailer towing. Manual transmission fluid doesn't require change. 0 Inspect shields and underhood insulation for damage or looseness. Adjust or replace as required.This is a Noise Emission Control Service. Applicable onlyto vehicles sold in the United States. 0 Check the air intake system installation to assure that gaskets are properly sealed and that all hose connections, fastenersand other components are tight. Also check to be sure that the air cleaner housing is properly seated, the cover fits tightly and the wing nuts are tight. Tighten connections and fasteners or replace damaged parts as necessary. This is a Noise Emission Control Service. Applicable only to vehicles sold in the United States. If your engine has a thermostatically controlled cooling fm, inspect a l l hoses and ducts for proper hook-up (or every 12 months, whichever occurs first).Be sure the valve works properly. This is a Noise Emission Control Service. Applicable only to vehicles sold the in United States. 7-75