ENGINE MAINTENANCE - Maintenance Procedures Engine Valves Procedures and maintenance intervals for initial service and routine maintenance of valves. Perform these valve clearance maintenance procedures according to the following intervals. 2 Engine Valve Adjust Intervals 1. Inspect and adjust valve clearance at intial servicing and at scheduled maintenance (if necessary). 2. Reset valve lash, if needed, to nominal specifications. See Engine Specifications on page 37. 3. Replace valve cover gasket seal at intial servicing and at scheduled maintenance.
Y53-1166-1G1 (08/2018) 79 Vehicle Application Interval Valve Adjust Interval Normal Duty (Line Haul) - less than 20% idle time Initial adjust at 150,000 miles (240,000 km, 6,750 hours), at 450,000 miles (725,000 km, 13,500 hours), then every 300,000 miles (480,000km) thereafter Normal Duty (Line Haul) - more than 20% idle time Severe Duty (Vocational*) Initial adjust at 60,000 miles (96,000 km, 1,600 hours), at 360,000 miles (576,000 km, 9.600 hours), then every 300,000 miles (480,000km) thereafter * Vocational vehicle applications include:
Agriculture, Concrete Mixers, Construction, Crane, Dumps, Emergency/Fire, Heavy Equipment, Loggers, Mining, Oil Field, Refuse, Pick-up & Delivery, Snowplows, and Wrecker.