Royal Enfield 500 TWIN 1949 Workshop Maintenance Manual page 23

ROYAL ENFIELD WORKSHOP MANUAL
(The other studs have already been removed to
take the engine out of the frame.)
The two halves of the crankcase can now be
separated.
The inner race of the roller bearing on the
timing side will remain on the crankshaft
bringing with it the cage and rollers and leaving
the outer race fixed to the crankcase.
The inner race of the ball bearing on the
driving side is a tight fit on the shaft and can be
removed with special tool No. E.5121. If this is
not available, the shaft can be driven out with a
hide mallet or a soft metal drift.
To avoid damage to the ball bearing the case
should be heated to about 100°C. before doing
this.
4. Main Bearings
To remove the ball bearing from the driving
side crankcase, heat the crankcase to about 100°
C., by immersion in hot water or in an oven,
after which the bearing can be driven out using
a drift which applies pressure to the outside
race only.
When fitting a new ball bearing, heat the
crankcase in the same way and use the same
drift, taking great care to keep the bearing
square with the bore.
To remove the outer roller race from the
timing side crankcase, first heat the crankcase,
then drive the race out using a small punch
through the three holes provided.
The inner race and rollers can be withdrawn
from the crankshaft using a claw-type extractor.
When refitting the inner race, drive it on to
the shaft until just flush with the end and no
further.
5. Fitting the Connecting Rods.
To remove the connecting rods from the
crankshaft, first take out the cotter pins securing
the socket screws in the connecting rods and then
remove the socket screws themselves.
If the big end bearing caps are removed to
examine the condition of the bearings, make sure
that the caps are refitted the same way round on
the same rods and that the rods themselves are
refitted the same way round on the same crank
pins.
In refitting the connecting rods, the socket
screws should be tightened progressively with a
torque wrench set at 200-220 inch-lbs.
If the cotter pins do not come in line remove
the socket screws and use a different thickness
of washer. A difference of -005 in. in the washer
alters the position of the screw 1/8 of a turn.
There is a recess in one side of the connecting
rod for a cotter pin head and this side must face
outwards when the connecting rod is assembled
on the crankshaft to avoid fouling between the
cotter and the crankshaft web.
Section D1 Page 2
White-metalled steel liners are fitted in the
connecting rods and these are replaceable.
6. Re-assembly of the Crankcase
Fit the outer roller race in the timing side
crankcase, the ball bearing in the driving side
crankcase and the inner roller race on to the
crankshaft as described in Subsection 4.
Heat the timing side crankcase with the outer
roller bearing race in position to about 100°C.
Lay the crankcase flat on the bench and insert
the shaft, with the inner roller race in position,
arranging the connecting rods so that they do not
foul the crankcase.
Insert the camshafts in their correct position
(exhaust front, inlet rear) and see that the filter
housing is in position.
Put the distance piece in position on the
driving side of the crankshaft.
Apply jointing compound to the timing side
crankcase.
Heat the driving side crankcase and bearing
to 100°C. and drop it over the crankshaft,
making sure to lift the tappets clear of the
cams.
Bolt the two halves of the crankcase together.
The crankcase should now be drawn into its
correct position by fitting the engine sprocket