Royal Enfield CONSTELLATION 1958 Workshop Maintenance Manual Download

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Turn the crankshaft until the connecting rods

are at bottom dead centre and the two halves of
the crankcase can then be separated, tapping the
crankcase with a soft mallet.

The inner race of the roller bearings on the

timing side will remain on the crankshaft
bringing with it the cage and rollers and leaving
the outer face 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
degrees  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 refitting 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The inner race and rollers can be withdrawn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 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 approximately
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.

If it is necessary to replace the big ends, a

service crankshaft can be supplied with
connecting rods fitted.

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 the crank-
shaft as described in Subsection 4.

Be sure that the inner race is driven on just

flush

with the end of the crankshaft and no

further.

There are several methods of assembling the

crankcase.  If  the  timing-side  is  fitted  to  the
crankshaft first, care must be taken not to score
the  inside  of  the  case.  If  the  driving-side  is
fitted  first

it is possible, with some makes of

roller bearing, though not probable, to drop one
of the rollers into the crankcase and cause
serious damage to the engine.

(a)

Timing-side First.

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).

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  crankshaft  should  now  be  drawn
into  its  correct  position  by  fitting  the  engine
sprocket  temporarily  and  tightening  the  nut
whilst the crankcase is still hot.

(b)

Driving-side

First.

Support

the

crankshaft  with  the  driving  end  pointing
upwards  and  place  the  distance  piece  in
position.  Heat  the  drivingside  crankcase  to
about 100° C. and place it over the crankshaft.
Fit  the  engine  sprocket  and  tighten  the  nut
while the crankcase is still hot.

Invert the crankshaft and crankcase and sup-

port it on two blocks of wood or a large block
with a hole in it.

Insert the camshafts in their correct position

(exhaust front, inlet rear).

Apply jointing compound to the driving-side

crankcase.

Heat the timing-side crankcase (with the

outer roller race) to about 100° C. and drop it

Section D10 Page 2

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