Page 81
3. Use hollow drift 87 90 891 to press out
the bearing from the sprocket.
Assembly
1. Fit the circlip to the upper sprocket
and press the bearing into the sprocket,
see illustration. Tool, hollow drift
8790 859, Fit the cirelip for the
bearing's outer race with the chamfer
facing outwards.
2. Fit the chains, sprockets and chain ten-
siomer. as described jin the section on
transmission assembly.
3. Tamupp with oil.
471—42
Page 82
Input shaft, bearing housing
Removing
1. Remove the oil catcher from the bear-
ing housing and press the input shaft
oul of the bearing housing. Retain the
front bearing, the spacer and the shims.
Use the ring-shaped support 83 90 098,
2. Take care that the connection pipe is
not damaged when pressing out the
shaft.
3. Press the rear bearing off the input
shaft. Use support 87 90 636 and ring
87 90 933.
471-43
Page 83
4. Remove the bearing races from the
housing with a drift. Rest the housing
on the ring-shaped support.
Input shaft and bearing housing
1.Connecting pipe, 8.Ball bearing
| lubrication 9.Race
2.Input shaft 10. Sprocket
3.Ball bearing 11. Nut
4,Race 12. Rear oil catcher
5.Bearing housing 13. Front oil catcher
6.Shims 14. Bolts
7.Spacer
Assembly
1. Press the rear bearing onto the shaft.
Use drift 78 41 075 and the ring-shaped
support.
:
if 2. Press the bearing races inta the bearing
Pe! housing. Use tool 83 90 312, 83 90 189
and the ring-shaped support.
471—44
Page 84
3. Fit the input shaft, shims, spacer and
bearing in the bearing housing. Select
shims and spacer of known size Lo deli-
berately give axial play. Place the
shims between the rear bearing and the
spacer.
4. Lubricate the bearings and press Lhem
together until they meet the distance
stop with a 3 Lonne force applied.
While the bearings are being pressed
together rotate the bearing housing,
against both the upper and lower bear-
ings, 40 times in both directions so thal
the balls become properly positioned.
Use drift 78 41 075 and the ring-shaped
support to avoid damaging Lhe connect-
ing pipe. Maintain the 3-tonne force.
5. Fit the gauge in the bearing housing
bolt hole. First put the bearing housing
under load on the upper bearing and
then on the lower bearing, reading off
the axial play.
Shims of sizes 0.10, 0.15, 0.25 and 0.50
mm are available for eliminating the axial
lay.
When correctly shimmed, there should be
no resistance to movement nor any play in
the bearings. If the play cannot be elimi-
nated by the available shims sizes, change
the spacer. Spacers are available in thick-
nesses of 8.08, 8.09, 8.10 and 8.11 mm.
471-45
Page 85
6. Press the front bearing off the input
shaft and fit the estimated number of
shims. Place the shims between the
rear bearing and Lhe spacer. Refil the
front bearing on the input shaft in the
bearing housing and press Lagether with
3-tonne force. Rotate the bearing as
described in point 4. Ensure that there
is no resistance Lo movement or play in
| the bearing.
7. Fit the oil catcher in the bearing hous-
| ing.
Gear selector mechanism
Refer to the section on dismantling and
refitLling.
The gear selector mechanism consists of a
I} system of selector shafts, selectors, selec-
tor forks with plungers, selector balls, ball
springs and taper setscrew,
471-46
———
"t ; el 5 I
a etl
fe |
1.Selector fork, Ist and 2nd speeds
2.Selector fork, 3rd and 4th speeds
3.Selector fork, 5th gear
4. Actuator, reverse gear
>.Actuator, 5th gear
6.Shaft, Ist and 2nd speed, 3rd and 4th
speed selector forks
7.Shaft, reverse actuator and 5th speed
selector
8,.Selector shaft
9.Reverse operating lever
10. Taper setscrew, shaft itern 7
11. Ball, selector
12. Spring, ball
13. Plunger
14. Cylindric pin
Page 86
Eee
Selector shafts
Dismantling
Knock out the dowl with a 4 mm drift.
Remove the spring, double lockout and
actuator.
Assembly
Assembly is in the reverse order. For posi-
tioning of parts see illustration. Fit new
dowels.
The reverse lever need not be det-
ached from the gear shift shaft when
the shaft is removed. The bolt is liable
to shear because of the locking of the
threads.
Replacing the seal and plastic bearing on
the gear selector rod
(Can be done with the gearbox in situ)
Removal
l. Knoek off the front taper pin from the
gear shift joint and separate the joint
from the rod.
2. Drain Lhe transmission oi] and remove
the differential housing cover.
1. Shaft
2. Actuator
3. Double lockout
4. Spring
5. Tubular dowel
1. Plastie bush
2. Sealing ring
3. Dismantling tool
4. Assembly tool
ein 3
471-47
Page 87
3. Put the dismantling tool 87 90 677 over
the collar on the sealing ring and bolt. in
the bolt of the tool against the shaft.
4. Pry off the sealing ring using of a
boltdriver held between the tool and
one of the boll heads on the differential
caver.
5. The plastic bush can now be removed.
Fitting
1. Fit the plastic bush.
2. Fit the new sealing ring with using the
sid of assembly tool 8790685 and a
suitable hammer.
. Fit the differential housing cover.
Assemble the gear shift rod joint and
the gear shift rod and fit the taper pin
5. Fill the transmission with oil.
Fw
Note
Before refitting remove any burrs or
marks on the gear selector rod.
Synchromesh
Synchromesh rings
When changing the synchromesh rings, fol-
low the instructions for the dismantling of
the gearbox. The differential unit must be
removed and the layshaft gear cluster dis-
mantled so that the primary gear housing
can be removed. When changing the syn-
chromesh ring for top gear, no further
dismantling is necessary.
When changing the synchramesh ring for
Ist and 2nd speed gear, the pinion shaft
must be taken out of the transmission
hausing, so that the gears can be removed
from the shaft.
Dismantling
Remove the circlip securing the synchro-
mesh ring Lo Lhe gearwheel. To remove the
synchromesh ring for fifth gear, remove
the circlip adjacent to the guide ring. The
circlip adjacent Lo the synchromesh ring
need not be removed.
471-48
Page 88
a
Fitting
First fit the quide rings for the retaining
springs, and the circlips for the quide rings
on 3rd and 4th gears. There are no circlips
on the guide rings for first and second
gears. Fit the retaining spring with the
longer end adjacent to the guide ring and
with the ends spanning 11 teeth.
There are no circlips on the guide rings for
first and second gears. Fit the retaining
spring with the longer end adjacent to the
guide ring and with the ends spanning 11
teeth.
gears are factory-fitted and peened in
} Position by a special Lool after the
circlip has been fitted. The guide rings
The guide rings on the third and fourth i
supplied as spare parts should not be
peened.
Guide 87 U2 730, which is available as a
spare part, should be used in conjunction
with a pear-shaped circlip, 87 02 722.
Alternatively, a complete synchromesh
unit comprising the gear and factory-fitted
synchromesh is available as a spare part,
No. 87 11 632.
Fit the 5th speed synchro ring. The retain-
ing spring should be positioned so that
there are 5 teeth between the ends of the
spring. Then fit the guide ring and the
circlip.
The synchro ring for 2nd and 3rd gears has
a molybdenum-coated cone; the same Llype
may also be used for Ist and 4th gears.
Synehromesh unit, lst and 2nd speed gear
l. 2nd speed gear
2. Guide ring
3. Retaining spring, 2nd speed qear
4. Synehramesh ring
5. Circlip
6. Synehromesh hub
7. Synchromesh sleeve
8. Retaining spring, lst gear
9. lst gear
471—49
Page 89
™ ——————
Sa
VentilaLion
Ventilation of the transmission is by means
of a hole through the top conver in the
primary gear housing. The hole emerges at
the centre of a plastic propeller which is
screwed to the clutch shaft.
As the clutch shaft rotates, the oil is flung
away from the hole by the propeller.
When the shaft is stationary, the oil level
in the primary gear is well below the hole.
Synehromesh, 3rd gear
« Loek ring
- Synchromesh ring
» Retaining spring, 3rd gear
- Guide ring
. Guide-ring cirelip
. 3rd gear
Bu Pwr
Bile ly
- Synchromesh sleeve
- Circlip
- Synchro cup
» Synchro hub
. Retaining spring
. Guide ring
-Cirechip
SAW wre
Page 90
Differential and pinion/
crown wheel gear
General
The crown wheel and pinion are a malehed
pair, so if one is exchanged the other must
be exchanged too. The parts are tested
together for noise and the oplimum setting
for minimum noise output is measured. The
key measurements for pinion and crown
wheel are the distance from the end face
of the pinion to the centre of the crown
wheel, and the backlash between the teeth.
These measurements and the mating num-
ber are sLamped on both parts at the time
of noise testing. When the pinion and crown
wheel are installed, these measurements
must be accurately adjusted with shims and
a special measuring instrument. The pinion
gear shims are placed next to the bearing
housing of the pinion shaft bearings, and
the crown wheel (differential) shims are
distributed between the two differential
bearing seats.
Adjusting the position of the pinion gear
General
Data for adjustment of the distance from
the pinion gear to the centre of the crown
wheel are stamped into the end face of the
pinion (an example is illustrated below).
End face of pinion
3 ~ measurement for pinion setting
RI13 mating number, also stamped on
crown wheel
0 — pinion nat offset - shaft centre-
line intersects crown wheel cen-
terline (all pinions are marked 0
and this datum has no relevance
to Lhe adjustment)
Important
Before dismantling the transmission,
always measure the positions of the
pinion and crown wheel. This provides
a check on whether the setting may
have been wrong. If the pinion shaft
and crown wheel assembly has done
less than 6,000 miles (10,000 km), the
setting can be adjusted, but after
greater mileage, when the gears will
have worn themselves into a certain
Position, the parts should be reas-
sembled with the same setlings as
were measured prior to dismantling.
Before measurin
The following preparations must be made
prior Lo measuring the pinion gear setting:
The following applies to manual transmis-
sions: The pinion shaft bearings must be
compressed until the torque required to
rotate the pinion shaft in the housing is 2.5
+ 0.5 Nm (25 + 5 kgfem), corresponding to
a dynamometer reading of 47-71 N (10.4
15.4 Ib, 4.7-7.0 kgf). These figures apply to
new, lightly oiled bearings. The corre-
sponding figures for older bearings (which
have done more than 1,200 miles (2,000
km) are 1.3 + 0.5 Nm (13 + 5 kgfcm), the
dynamometer readings being 19-43 N (4.2-
9.5 Ib, 1.9-4.3 kgf).
The differential unit must be removed to
permit installation of the measuring instru-
ment (tool 8390 155), which consists af a
measuring jig with attached dial indicator.
A ground gauge block is provided for cali-
bration of the dial; the block is daid against
the calibration stops of the instrument, and
the distance between these stops and the
centreline of the tool is exactly 2.362 in
(60.000 mm), equal to the distance from
the end face of the pinion shaft ta the
centre of the crawn wheel (see illlustra-
tion). The procedure for measuring the
pinion gear position is as follows.
pinion
Rasic measure
$4075
473-1
crown wheel