Royal Enfield 500 TWIN 1949 Workshop Maintenance Manual Download

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ROYAL ENFIELD WORKSHOP MANUAL

Section L2 Page 2

the wheel out of the fork ends, tilting it so as to
disengage the end of the brake shoe pivot pin from
the slot in the fork end.

When replacing the wheel make sure that the dogs

on  the  speedometer  drive  gearbox  are  engaged  with
the slots in the end of the hub barrel. Make sure also
that  the  speedometer  drive  gearbox  is  correctly
positioned  so  that  there  is  no  sudden  bend  in  the
driving  cable.  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 while the brake is off, while at the
same  time  only  a  small  travel  of  the  brake  pedal  is
necessary to put the brake on.

3. Removal of Brake Shoes

for Replacement,

Fitting New Linings, etc.

Remove the complete wheel as described above,

then remove the left hand spindle nut, chain adjuster
and  distance  collar,  thus  permitting  the  complete
brake  cover  plate  with  operating  cam,  pivot  pin,
shoes  and  return  springs  to  be  lifted  off  the  hub
spindle.

In the case of the 7 in. brake fitted to the "Meteor

700" and "500 Bullet" models, the brake shoes can
then be removed, after detaching the return springs.

In the case of the 6 in. brake fitted to the "500

Twin"  and  "350  Bullet"  Models,  unscrew  the  pivot
pin  locknut  and  the  operating  lever  nut,  after  which
the assembly of the brake shoes, return springs, pivot
pin  and  operating  cam  can  be  removed  from  the
cover plate by unscrewing the pivot pin and applying
light blows with a hammer and drift on the end of the
operating  cam.  The  return  springs  can  then  be
unhooked  from  the  spring  posts  in  the  brake  shoes,
thus allowing the whole assembly to fall apart.

4. Replacing Brake Linings

Brake linings are supplied either in pairs ready

drilled complete with rivets, Part No. 37786BX (6 in.
shoes)  or  37787BX  (7  in.  shoes),  or  ready  fitted  to
service  replacement  brake  shoes,  Part  No.  38042  (6
in.  shoes)  or  38043  (7  in.  shoes).  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.

5. Removal of Hub Spindle and Bearings

To remove the hub spindle and bearings, having

already removed the brake cover plate assembly and
speedometer  drive  gearbox,  lift  out  the  felt  washers
and  distance  pieces  then  hit  one  end  of  the  spindle
with a copper hammer or mallet thus driving it out of
the hub, bringing one bearing with it and leaving the
other in position in the hub. Drive the bearing off the
spindle  and  insert  the  latter  once  more  in  the  hub  at
the  end  from  which  it  was  removed.  Now  drive  the
spindle  through  the  hub  in  the  opposite  direction,
when it will bring out the remaining bearing.

6. Hub Bearings

These are deep groove single row journal ball

bearings.  The  lighter  bearings  used  in  the  "350
Bullet" and "500 Twin" hubs are 5/8 in. i/d by 1.9/16
in.  o/d  by  7/16  in.  wide.  The  Skefko  Part  No.  is
RLS5.  Equivalent  bearings  of  other  makes  are
Hoffmann  LS7,  Ransome  and  Marles  LJ  5/8  in.,
Fischer LS7.

The heavier bearings used in the "Meteor 700"

and "500 Bullet" Models are 5/8 in. i/d by 1.13/16 in.
o/d by 5/8 in. wide. The Skefko Part No. is RMS5.
Equivalent bearings of other makes are Hoffmann
MS7, Ransome and Marles MJ5/8 in., Fischer MS7.

7. Fitting Limits for Bearings

The fit

of the bearings in the hub barrel is

important.  The  bearings  are  locked  on  the  spindle
between  shoulders  and  the  distance  pieces,  which  in
turn  are  held  up  by  the  cover  plate  nuts.  In  order  to
prevent  endways  pre-loading  of  the  bearings  it  is
essential  that  there  is  a  small  clearance  between  the
inner  edge  of  the  outer  race  of  the  bearing  and  the
back of the recess in either end of the hub barrel. To
prevent any possibility of sideways movement of the
hub  barrel  on  the  bearings  it  is,  therefore,  necessary
for the  bearings to be a tight fit in the barrel but this
fit must not be so tight as to close down the outer race
of  the  bearing  and  thus  overload  the  balls.  The
following  are  the  manufacturing  tolerances  which
control  the  fit  of  the  bearings.  The  figures  for  the
bearings  themselves  are  for  SKF  bearings  but  other
manufacturers' tolerances are similar.

"350 Bullet" "Meteor 700"

and "500 Twin" and "500 Bullet"

Bearing o/d     1.5622/1 5617 in.     1 8122/1 8117 in.
Housing bore  1.5620/1.5615 in.     1.8115/1.8110in.
Bearing bore    .6252/.6247 in.          .6252/.6247 in.
Shaft diameter .6252/.6248 in.          .6252/.6248 in.

8. Refitting Ball Bearings

To refit the bearings in the hub two hollow drifts

are required, as shown in Figs. 2 and 3. One bearing
is first fitted to one end of the spindle by means of
the hollow drift; the spindle and bearing are then

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