Royal Enfield 500 TWIN 1949 Workshop Maintenance Manual page 94

ROYAL ENFIELD WORKSHOP MANUAL
connecting link in the driving chain make sure
that the closed end of the spring link points in the
direction of travel of the chain. Replace the chain
adjuster cams in their original positions or, if
necessary, turn each of them the same number of
notches to tension the chain and maintain correct
wheel alignment. Do not forget to refit the brake
rod and adjust the brake so that the wheel turns
freely when the brake is off, while at the same
time only a small travel of the brake pedal is
necessary to put the brake on.
4. Removal of Brake Shoes for Replacement
Fitting New Linings, etc.
Remove the complete wheel as described
above, then remove the spindle nut, 36651, chain
adjuster and the distance collar, 39315, thus
permitting the complete brake cover plate with
operating cam, pivot pin, shoes and return
springs to be lifted off the hub spindle. The brake
shoes can then be removed after detaching the
return springs.
5. Replacing Brake Linings
Brake linings are supplied either in pairs
ready drilled complete with rivets, 37787BX, or
ready fitted to service replacement brake shoes,
38043. When riveting linings to shoes secure the
two centre rivets first so as to ensure that the
lining lies flat against the shoe. Standard linings
are Ferodo MR41 which are drilled to receive
cheese headed rivets.
6. Removal of Brake Operating Cam and
Brake Shoe Pivot Pin
The pivot pin is threaded into the torque
plate, from which it can be unscrewed after
removing the locknut 39351. (Note the Part
Number of the torque plate only is 36527 while
the thin pressed steel cover plate is 36526. These
two are riveted together and supplied as one unit
Part Number 32525).
To remove the operating cam unscrew the
nut, 10314, which secures the operating lever to
the splines on the cam. A sharp tap on the end of
the cam spindle will now free the lever after
which the cam can be withdrawn from its
housing.
7. Cush Drive
The sprocket/brake drum, 39301, is free to
rotate on the hub barrel. Three radial vanes are
formed on the back of the brake drum and three
similar vanes are formed on the cush drive shell,
39302. Six rubber blocks are fitted between the
vanes on the brake drum and those on the cush
drive shell, thus permitting only a small amount
of angular movement of the sprocket/brake
drum relative to the hub barrel and transmitting
both driving and braking torques and smoothing
out harshness and irregularity in the former.
If the cush drive rubbers become worn so that
the amount of free movement measured at the
tyre exceeds 1/2 in. to 1 in., the rubbers should
be replaced. To obtain access to them remove the
complete wheel as described above, then
unscrew the loose section of the spindle, 39336,
completely and also the three attachment bolts,
39316. The main portion of the wheel can then
be lifted away from the assembly consisting of
the fixed section of the hub barrel, fixed portion
of the spindle, sprocket/brake drum complete
with brake and the cush drive shell. Now remove
the brake cover plate complete with brake shoes
as described above, thus giving access to the
three cush drive ring locking pins, 8718.
Unscrew these and then unscrew the cush drive
pins, 39310, thus enabling the sprocket/brake
drum to be separated from the cush drive shell,
after which the six cush drive rubbers can be
lifted out.
When reassembling the cush drive the entry
of the vanes between the rubbers will be
facilitated if the latter are fitted into the driving
shell first and then tilted. The rubbers should be
liberally painted with soapsuds to facilitate entry
of the vanes. The three cush drive pins, 39310,
should be tightened as far as possible and then
slackened back half to one turn to enable the
locking pins, 8718, to be fitted.
When reassembling the cush drive, coat the
inside of the bore of the sprocket/brake drum
liberally with grease where it fits over the hub
barrel. Put grease also behind the washers on the
three cush drive pins, 39310.
Section L1 Page 3