Overhauling the stuffing box on 42 to 98 MC engines
dismount the cylinder cover see instruction book vol 2 procedure 901
loosen the stuffing box and piston rod foot
Mount distance pieces to protect the stuffing box the telescopic pipe is
fitted either to the guide shoe or to the cross head pin if the telescopic
pipe is fitted to the cross head pin it must be disconnected and suspended
before removing the piston and piston rod
ensure that where ridges are smooth out and that any carbon deposits are removed
also make sure that the piston cleaning ring if installed is removed from the
top of a cylinder liner mount the lifting tool and lift the piston with
piston rod and stuffing box out of the engine place protective covers over the
cross head and in the bottom of the cylinder unit remove the cover from the
cutout in the gallery floor plate and land the piston on the support tool
before starting the overhaul tape a new o-ring to the piston rod above the
stuffing box housing
insert lifting eye bolts and lift the stuffing box to a comfortable working
height mount the work table around the piston rod
remove and discard the o-ring loosen and remove the assembling bolts under fitted
bolts remove the stuffing box halves do not use a chisel to separate the halves
as this will damage the contact phases
press all sealing rings and scraper rings down towards the work table push
the segments together so the total ring end clearance can be measured at one
point measure and record the clearances and compare them with the wear limits
given an instruction book connect the hooking tool remove the springs and
segments and keep them together in the same position as when they are fitted in
the stuffing box
clean and inspect any segments which are to be used again the stuffing box is so
designed that it has the same time between overhauls as the piston the
lamellas are normally due for replacement at each overhaul while the
sealing rings normally only need to be replaced at every other overhaul after
cleaning insert all segments in their respective grooves in the housing and
measure the vertical clearance with a feeler gauge see instruction book volume
2 procedure 902
check the calibration of the springs see instruction book of volume 2 procedure
902
check the surface condition and the diameter of the piston rod record the
results for example on this inspection report which is available from ma an B&W
diesel lubricate the piston rod with molybdenum disulphide check that the
lamellas can be moved remove any burrs which may have been caused during the
measuring of the ring and clearance from the ends of the segments assemble all
ring units making sure that the markings on the various segments match each other
to facilitate the mounting of the Springs cross your arms before
connecting the hooking tools remove any burrs from the ends of the segments
make sure that the guide pin between the sealing ring and the covering engages
correctly lift all the Rings up the piston rod and use a stuffing box halves
to adjust the Rings so that they fit properly in the grooves ensure that the
ring end clearance is evenly distributed all the way around
apply lubricating oil to the segment and to the housing press the stuffing box
halves into place around the segments
adjust the torque spanner to the value given in the instruction book finally
tighten the nut to the required torque and mount the o-ring in the groove in
the housing
make sure that the guide pins on the distance pieces engage correctly with
the stuffing box
making sure the cylinder liner is clean mount the piston with piston rod and
stuffing box as described in the instruction book
reinstall the cover on the gallery floor plate remove the protective cover in the
bottom of the cylinder unit carefully clean oil and sludge from the stuffing
box flange to ensure the correct contact between the stuffing box and the flange
remove the protective cover from the cross head as late as possible finally
secure the piston rod foot stuffing box and telescopic pipe and mount the cinder
cover