ROYAL ENFIELD 350cc O.H.V. WORKSHOP MANUAL
Page 41
SUPPLEMENT
F0R
ROYAL ENFIELD 350 c.c. O.H.V. MODEL WD/CO/B
FITTED WITH BURMAN GEARBOX
Contract No. 294/C/13870
Frame and Engine Nos. 14001-17000 inclusive
CLUTCH.
104. Dismantling, Reassembling and Adjustment
of Control.
Machines having frame numbers 14001-15050
inclusive are fitted with clutches identical with that
described in paragraphs 32 and 33 (page 22) and
illustrated in Fig. 30 (page 20) of the main portion of
this book. Later machines have a similar clutch with a
solid centre instead of the cush drive centre. This is
illustrated in Fig. 62 and the methods of dismantling
and assembling the clutch and adjustment of the
clutch control are exactly the same as for the clutch
fitted to the standard gearbox.
GEARBOX.
105. Method of Operation.
The method of operating the foot control lever is
precisely the same as with the standard gearbox, i.e.
the lever is moved downwards when making upward
changes and upwards when making downward
changes. The internal construction of the gearbox is,
however, completely different and is shown in Fig.
66.
The mainshaft (3) runs in the 32 T. driving gear
(12) and carries on its splined centre portion the
mainshaft sliding gear (13), which has a gear at each
end. The mainshaft third gear (15) runs free on the
mainshaft.
The layshaft (36) carries the layshaft third gear
(29) and layshaft small gear (34) or constant mesh
gear on splined portions at each end of the layshaft.
The layshaft first gear (30) and second gear (33) run
free on the shaft while the layshaft clutch (31) is free
to slide on the splined centre portion of the shaft.
The gears are engaged by endways movement of
either the mainshaft sliding gear or the layshaft clutch
which are controlled by operating forks actuated by a
camshaft which is operated by the footchange
mechanism.
The illustration shows the gears in the neutral
position. Rotation of the mainshaft causes rotation of
the mainshaft sliding gear and the first and second
gear pinions on the layshaft. As, however, these are
free to rotate on the layshaft there is no drive through
the gearbox.
To obtain first gear the layshaft clutch is moved
to the right so that the external teeth on it engage with
the internal teeth in the layshaft first gear, thus
clutching the gear to the layshaft. Rotation of the
mainshaft now causes rotation of the layshaft through
the mainshaft sliding gear, layshaft first gear and
layshaft clutch. In turn, this causes rotation of the
driving gear through the layshaft small gear.
To obtain second gear the layshaft clutch is
moved to the left, thus clutching the layshaft second
gear to the shaft so that rotation of the mainshaft
causes rotation of the driving gear, through the
second gears, the layshaft and the layshaft small gear.
To obtain third gear the layshaft clutch is
returned to its central position, thus freeing both the
first and second layshaft gears on the shaft and the
mainshaft sliding gear is moved to the right so that
the teeth on the smaller end of it engage with the
internal teeth in the mainshaft third gear, thus
clutching it to the mainshaft. Rotation of the
mainshaft now drives the layshaft through the third
gears and in turn drives the driving gear through the
layshaft small gear.
To obtain top gear the mainshaft sliding gear is
moved to the left so that the teeth on the larger end of
it engage with the internal teeth in the driving gear,
thus clutching the mainshaft direct to the driving gear.
The clutch is mounted directly on the mainshaft
and the driving sprocket is attached to the splined end
of the driving gear. Thus connection between the
mainshaft and the driving gear either direct or
through one of the gear trains causes the rear wheel to
be rotated by the engine at a speed depending on the
gear ratio which is in use.
The kickstarter is operated by means of a
quadrant which, on depressing the kickstart lever,
engages with a ratchet pinion on the end of the
mainshaft.
106. Removal of Gearbox from Frame.
The gearbox is removed from the frame in the
same way as the standard box (see paragraph 13, page
10, in the main portion of this book).
All operations on the gearbox can, however, be
carried out with the box in position.
www.hitchcocksmotorcycles.com