GEAR 4Y0155 - Caterpillar

3400 Family of EnginesReference: All Operation and/or Maintenance Guides for the 3400 Family Of Engines in all applications.The recommended interval for intake and exhaust valve lash adjustment has been changed for the 3400 Family Of Engines. This includes the current and non-current 3400 Family Of Engines in all applications. (An earlier article in the September 3, 1984 Service Magazine and the current Guides show the new interval only for 3406B Truck Engines.) The new recommended interval is:
"Adjust the intake and exhaust valve lash at the first oil change (12,500 mi or 20 000 km for on highway truck engines). After that, adjust the valve lash every 2000 Service Hours (100,000 mi or 161 000 km for on highway truck engines), or once a year".
This new recommendation will help extend the service life of the valve train parts. Formerly, there was no adjustment recommended until 2000 Service Hours, or one year. Be sure to note this change in all the affected Guides.