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F
THE GEARBOX
GENERAl. DESCRIP110N
The
gearbox
has four forward speeds and one reverse.
Top
gear is obtained by
direct drive. third
and
second
by
gears in constant
mesh, and first and
reverse
by
sliding spur gears.
A propeller
shaft driving
Oange
is
fitted at the rear
end
of the
third motion
shaft.
Section
F.l
REMOVING
THE GEARBOX
Remove the power
unit
as described in Section A.24.
Remove the
starter
motor,
unscrew
the
bolts
and
nuts
securing the
hell
housing
and exhaust
pipe support
brackets,
and withdraw the
gearbox
and rear extension
from the engine.
Take
care
to
keep
the
gearbox
Oange
parallel with
the
crankcase face
until
the first motion
shaft
is
clear
of
the
clutch.
Section
F.2
DISMANTLING THE
GEARBOX
Extract
the dipstick, drain plug, and speedometer
drive.
Unscrew
the nuts and remove
the
gear lever
remote
control
tower and
joint washer.
Remove
the
nul and spring
washer
securing
the
propeller shaft driving
flange and
withdraw the
Oange.
Use
service
tool t8G34A to hold the ftaoge
while
the nut
is
removed.
Unscrew and remove the s ix bolts and
the
rear exten-
sion
cover and
joint
washer.
Remove
the
interlock arm
and bracket.
Remove the
two nuts and six set screws
securing
the
gearbox extension
to
the
gearbox.
Pull
the extension
from
the
gearbox,
a
t
the same time manreuvring the
remote control shaft selector
lever
from the
selectors.
U
nscrew the
three
countersunk screws and the
seven
hexagon-headed
set
screws holding the
gearbox
cover;
remove
the cover and ovcrshoot stop.
Cut the locking wire and unscrew
the
three
change
speed fork
set
screws.
Unscrew the two
set screws and remove the shifter
shaft locating block with
shifter
shafts
from the gearbox;
note the two
dowels
in the block; take care
to
catch
the
three selector balls
and
springs.
Withdraw
the forks from
the
box
in
the
followin&
order-reverse, top and
third,
and first and second.
Unsc.-ew
the
clutch lever pivot nut; screw out the
pivot bolt and remove
the
lever with the
thrust
bearing.
Unsc.-ew
the nuts and remove the gearbox
front
cover;
note the bearing
shims
between the
cover
and the bearing.
F.4
Tap
out the
layshaft,
allowing the gear cluster to rest
in
the bottom of the box.
Unscrew
the retaining set screw
and
remove the reverse
shaft and
gear.
Withdraw
the mainsbaft assembly
to the
rear.
Withdraw
the first motion
shaft
complete with 18
spigot
needle
rollers.
Lift
out the
Jayshaft
gear cluster and the two
thrust
washers.
Rear
extensioo
Release
the front and rear selector levers from the
remote
control shaft by removing
the clamping
screws
and
sliding
the
levers from the rod. Extract
the
keys
from the shaft and withdraw the remote
control
shaft
from
the
rear
extension.
Section
F.3
DISMANTLING THE
THIRD
MOTION
SHAFT
Remove the following items in this order: baullc: ring.
synchromesh
sleeve
and hub, second baulk ring. If the
synchromesh sleeve
is
removed from the bub take
care
not
to lose
the
three
locating balls and springs which
will be released in consequence.
Press down
the
third
speed gear cone
thrust washer
plunger
;
rotate
the
thrust
washer to align its splines
with
those on the shaft and
remove the
washer.
Withdraw
the third speed
gear
and its splined bush.
Withdraw the bush interlocking washer to
release
the
second speed
gear
with its bush and baulk ring,
Remove the thrust washer from
the
splines
on
the
shan and withdraw the first SJJd second
Speed
hub and
gear; if neeessary, slide
the
gear
from
the
bub,
taking
care
not
to
lose the three balls and
springs.
Tap
up the locking tab and unscrew
the
rear
retaining
nut; withdraw the
washer,
speedometer drive
gear
and
key, and the distance
sleeve
from the
shaft.
Press the
rear
bearing and housing
from
the
shaft.
Section
F.4
ASSEM.
B LING
THE
TIDRD
MOTION
S
HAFT
Assemble
from the front end.
(1)
Locate the rear thrust washer
on the
front end
of
tbe splines, ground face to
the
front.
(2)
Push
UJC
louger
brass
bush
up
tu
the
splim:s with
tbe dog towards the
front.
NOTE.-
This bush
must
be
fitte.l
so that
tbe oil
bole
Is
ill
line
witb
tbe oae
in tbe
sllaft
ucl tbe
aot-away
portioa of
tbe
tbinl speed
splille.! basil
will be
on~
the
loc:atiag peg
bole
wbeB
tbe <lop
MOA
(Twill
Caul).
Is:!ue
3.
21765
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