William Jordan, Valve lash is not necessary if the measurement of the valve lash is in acceptable
range. Check the valve lash while engine is stopped. Note: the Correct valve lash setting for
C-12 engine. ( Intake Valves 0.015 +, - 0.003 ), ( Exhaust Valves 0.025 =,- 0.003 ) what
this is telling you ( there is 0.006 gap if feeler gauge will slide for adjustment, no adjustment is
necessary ). There has been many thoughts on correct setting of valve lash that been passed
around that is incorrect. Correct for lock nut torque if valve lash adjuster is moved is 22 +, -
foot lbs. Looking at your milage and removing valve cover checking adjustments more than
likely adjustment will not be necessary as per above info. with valve adjustments taking into
Cat specs the plus and minus measurement of intake and exhaust valves. Again there has been
many different thoughts on correct valve adjustment and again cat specs has not change from
above, Dave Atherton Retired Cat Mechanic