1999 Volvo Penta "WT" Models Workshop Manual, Page 182Get this manual
m 3Valve lifter guide retainer and boltsCD 4Valve lifter guides5Valve liftersRemove the valve lifters one at time using magnetPlace the valve lifters in the organizer rack, or tag them in way to ensure they can be returned to the valve lifter bore from which they were removed m mvarnish valve liftersThese be stuck in their bores due to Some may gum or depositsvalve lifters can be removed
using either 3049-A or 9290-01Clean: Parts in solventBlow dry with compressed air Make sure the oil passages in the valve push rods are clearInspect: Valve rocker arms and balls at their mating surfacesThese surfaces should be smooth and free from scoring or other damage Valve rocker arm areas that contact the valve stems and the sockets that contact the valve push rodsThese areas should be smooth and free of damage and wear Valve rocker arm nuts or boltsAll engines use prevailing torque nutsAt least 55 inlb{6,2 Nm} of torque should be required to thread the nuts onto the valve rocker arm studsIf not, it is possible that the nut(s} could back off during engine operation causing loss of lash and create valve train noise