Usage:
All Engines Used In All Applications
Reference: Service Magazine, September 3, 1984, Page 11, "Change To Maintenance Interval For Valve Lash Adjustment". Service Magazine, January 14, 1985, Page 11, "Valve Lash Adjustment Not A Warranty Item". Service Magazine, April 7, 1986, Page 3, "Adjust Bridge Whenever Valve Clearance Adjustments Are Made".
Valve lash adjustment procedures are being changed for all engines used in all applications in Caterpillar products (procedures for selected engine models were changed earlier).
Evaluations have determined that the greatest rate of change in valve lash adjustment occurs during the first few hundred hours of operation on a new, rebuilt or remanufactured engine. Therefore, Caterpillar no longer recommends a "predelivery" check of valve lash, because initial wear and seating of valve train components has not occured.
Intake and exhaust valve lash adjustments should be made at the first recommended oil change interval given in the individual product Operation And Maintenance Guide. Thereafter, follow the normal valve lash adjustment intervals. In addition, earlier publications used the term "check" valve lash in reference to valve train maintenance. It is more prudent and cost effective to adjust each valve to the given specification, rather than to "check" valve lash before adjusting.
NOTE: Operation And Maintenance Guides will be updated to reflect the above changes.