Four Speed Gearbox Removal/Installation/Dismantling/Assembly - Datsun 510 series Workshop Manual

FOUR SPEED GEARBOX Removal and Installation
The removal and installation procedures for the four speed
gearbox
are
similar
to
those previously
described for the three
speed gearbox However the floor mounted gear lever
must
be
removed from the controllevef bracket in addition to the
operations already
detailed
FOUR SPEED GEARBOX Dismantling
Drain the oil from the
gearbox
Remove the dust
coveT
and
release the spring securing
the clutch withdrawal lever Remove
the withdrawal lever and release bearing from the clutch housing
as
described in the section CLurCH Remove the clevis pin
securing the striking rod
to
the control lever
Remove the
speedometer
drive
pinion assembly
and with
draw the
rear
extension housing Disengage the striking
rod from
the selector rod gates Remove the gearbox
covers
See Figs F 26
and F 27
Unscrew the three detent ball plugs and
remove
the spriags
and detent balls Drive
out
the pins securing the selector forks
to
the rods and withdraw the forks and rods Lock the main
shaft
by moving
the first second and third fourth
coupling
sleeve
into gear
at
the
same
time and release the ffiainshaft
nut
Remove the countershaft and the
gear
cluster together
with the
two
needle roller bearings and
spacers
Remove the
snap
ring holding
the
revep
e
idler gear and withdraw the
reverse
idler gears and shaft
Fig
F 28
Take off the bolts
securing
the mainshaft bearing retainer
to
the gearbox
case
Fig F 29 Withdraw the mainshaft
assembly Fig
F30
and the main drive shaft
The mainshaft
can
be dismantled in the following
manner
Release the third fourth synchronizer
unit snap ring and with
draw the hub complete with coupling sleeve Remove the third
speed gearwheel
and the needle roller
bearing
from the main
shaft Take off the mainshaft
nut
and
locking plate
Remove the
speedometer drive gear with the retaining ball
Withdraw the
mainshaft reverse
gear and the hub Press off the mainshaft
bearing complete with the bearing retainer
Remove the thrust washer and the first
speed
gear
together
with the needle roller
bearing taking
care
not to
lose the small
baU used to
locate the thrust washer Slide off the first
speed
gearwheel bush Withdraw the first second synchronizer and
hub Remove the second speed gearwheel
and needle roller
bearing
FOUR SPEED GEARBOX
Installation
Refer
to
the instructions given for the three
speed
gearbox
and to
Technical Data for the
specifications applicable to
the
different
gearboxes
FOUR SPEED GEARBOX Assembly
Assembly
of the
gearbox
is similar
to
the
procedures
previously described for the three speed gearbox with the
following exceptions
When assembling the main drive gear
bearing
on
the shaft
insiall
the spacer and select
a new
snap
ring
to
eliminate all end
float between
bearing
and
snap
ring Snap rings are
available in
five thicknesses from 1 52
1 77mm 0 06 0 07 in
The assembly procedures
for the Warner type synchronizers
are
similar to
the instructions previously described for the three
speed gearbox
Refer
to
THREE SPEED GEARBOX Assembly
for further details
To assemble the Servo F4C63
type synchronizers proceed
as
follows
Place the gear
on a
clean flat surface and install the
synchronizer ring
on
the inner side of theclutch
gear
Fit the
thrust block into place
as
shown in
Fig F 3 1 Place the anchor
block and brake band into position and fit the circlip into the
groove
in the gear
to
secure
the synchromesh
assembly
When assembling
the mainshaft select
a
snap
ring
which
will give
an
end float between 0 05 0 15
mm
0 002 0 006in
to
the third speed gearwheel Snap rings
are
available in five
sizes from 1 40 mm 0 0551 in
to
160
mm
0 0630 in thick
ness
Tighten the locknut
at
the rear
of the mainshaft
to
a
torque
reading
of 7 1 kgm 51 87Ib ft
Assemble the
reverse
idler
gear as
shown in
Fig F 3 2 The
reverse
idler driven gear 3
should be
placed
on
the end of the
reverse
shaft 1 with the longest spline
and retained with
a
suitable snap ring 2 Install the reverse
shaft and gear assembly
into the
gearbox case
from the
rear
with the thrust washer 4
between the
gear
and the
case
Fit the thrust washer 5 and
idler
gear
6
18
teeth and
secure
with
a
suitable snap
ring
2 The end float of the
gear
should be checked and
adjusted
to
0 1 O 3 mm
0 004 0 012 in by selecting
a
suitable snap
ring 2 Five thicknesses of snap rings
are
available from I lmm
0 043in
to
1 5mm
0 06in See Technical Data for F4W63
and F4C63 gearboxes
Adjust
the
counter
gear end
float
to
0 05 0 15
mm
0 002 0 006in by selecting
a
thrust washer
of the
required
thickness Thrust washers
are
available in five
thicknesses from 2 4 0 2 60
mm
0 094 0 102 in
When
assembling
the selector mechanisms
Fig
F 3 3
fit
the first second selector forks I and the third fourth selector
forks 2
onto
the coupling
sleeves and insert the first second
fork rod 3
Fit
an
interlock
plunger 4 and the third fourth speed
selector rod 5 Do not
forget
the interlock
pin
7 A section
through
the selector and interlock mechanism is
given
in
Fig
F 34 Install
an
interlock plunger
6 and assemble the
reverse
selector fork 8 and fork rod 9
Secure the selector forks
to
the rods with the retaining pins
10
Place
a
check ball and spring into each of the holes and
screw
the plug
down
to
a
torque reading
of 1 7
2 1 Jegm
12 3 15 2 Ib ft after coating the threads with
sealing
com
pound
Install the
rear
extension
housing engaging
the striking rod
with the fork rod
gates
and
tighten
the
housing
bolts to
a
torque reading
of 16 2 5 kgm 12 18Ib ft
Fit the front
and bottom
covers
and tighten the bolts
to
a
torque
reading
of 1 1 18
kgm
8
13Ib ft
57