Flywheel And Flywheel Housing; To Remove The Flywheel; To Renew The Flywheel Ring Gear; To Refit The Flywheel - Perkins 4.108 Workshop Manual

SECTION P
Flywheel and Flywheel Housing
To Remove the Flywheel
1. Remove the gearbox, clutch assembly and any
linkage as detailed in the service literature applic-
able to the particular vehicle or application.
2. Knock back the locking tabs from the flywheel
securing setscrews.
3. Remove the securing setscrews and carefully re-
move the flywheel from the crankshaft flange.
To Renew the Flywheel Ring Gear
1. The flywheel ring gear is a shrunk fit on the fly-
wheel, its removal is carried out by partially cut-
ting through the gear and chisel cutting it from
the flywheel. An alternative method is to apply
localised heat to the ring gear to expand it
sufficiently to enable it to be tapped evenly from
the flywheel.
2. The locating faces of the flywheel should be
thoroughly cleaned to ensure a positive location
when the new ring gear is fitted.
3. Clean, then heat the new ring gear to a tempera-
ture not exceeding 480°F (250 Q C).
4. Fit the ring gear over the flywheel with the lead on
the teeth facing uppermost, i.e., facing away from
the engine when the flywheel is fitted. Rotate the
gear quickly on its location immediately it is fitted
to ensure it is laying flat, then allow to cool.
To Refit the
1"1",.11' .. "" .. 1
It is most essential to ensure that the crankshaft flange
face and periphery are perfectly clean and free from
burrs, similarly the mating face of the flywheel itself
before refitting of the flywheel is attempted. Failure to
ensure this may make it impossible to fit the flywheel
satisfactory within the various limits quoted hereafter.
It will be noted that there is a sixth (untapped) hole in
the crankshaft flange which will be at B.D.C. when
Nos. 1 and 4 pistons are at T.O.C.
The flywheel can only be fitted in one position due to
the irregular spacing 01 the setscrew holes.
1. It is advisable to screw a short stud into the crank-
shaft flange just finger tight, so that when the fly-
wheel is offered up this stud can take the weight
of the flywheel whilst the securing setscrews are
fitted, this stud can then be removed and re-
placed by the fifth setscrew.
2. Tighten the securing setscrews to the torque given
on Page B.2 but do not lock with the tab washers
P1
3. Set up a dial test indicator (clock) gauge with the
base secured against the rear face of the flywheel
housing and the gauge stylus at right angles to the
periphery of the flywheel. Turn the crankshaft and
check the run out, the flywheel should run truly
within 0.012 in (0,30 mm) total indicator reading
at this stage.
P2