Page 411
GEAR SHIFT MECHANISM
If the task in hand concerns the gear shift mechanism
only, it will suffice to lift the power unit out of the car
and remove the transmission case top cover and the end
cover.
Disassembly
1. Back off the screws holding the transmission case cov-
er and lift off the cover.
TRANSMISSION CASE COVER WITH SHIFTER MECHANISM
AND CATCH ASSEMBLY
1. Operating shaft 6. Catch shaft
2. Cover 7. Catches
3. Tension pin 8. Screw
4. Shifter yoke 9. Plug
5. Spacer
REMOVA
Febr 1977
2. Back off and remove the end cover bolts and loosen
the cover by inserting a slender screw driver between
the cover and the transmission case at both sides and
carefully prying it loose.
Proceed with great care, collecting the shims from
inside the cover and noting their locations at the
respective bearings. mas SEES wa
3. Remove the end cover, which will be accompanied by
two of the gear shift fork shafts. Collect the gear shift
fork poppet balls, which are ejected when the shafts
are removed.
4. Using an arbor, knock the reverse gear shift fork shaft
out from the rear. Collect the poppet bal! from the
fork, so that it does not drop down into the transmis-
sion case.
5. Lift out the three gear shift forks.
6. If any of the parts fitted in the top cover — shifter
yoke, shaft or catch — are to be renewed, the rivet or
counter sunk head in the cover must be drilled out.
After reassembly, fit a rubber plug or a self tapping
screw in the hole in the cover, this hole being provided
to permit the pin to be driven out of the shifter shaft.
L OF END COVER
NOTE |
471-19
Page 412
Reassembly
Before commencing reassembly, remove all gasket frag-
ments and all traces of old sealing compound.
1. Check Positively, for instance with the aid of a mag-
net, that none of the Poppet balls has dropped down
into the transmission case.
Place the synchronizer sleeves and reverse gear at
neutral and put in the three gear shift forks.
=
NOTE
The gear shift forks must be fitted with their springs
and poppet balls before being placed in the trans-
mission case. Hold the poppet ball in place with
tool 78 40 697.
TOOL 78 40 697 IS COLLECTED AS THE GEAR SHIFT FORK
7 SHAFT IS DRIVEN IN
4. Pass the two gear shift fork shafts on the end cover
through the end wall and into their respective forks.
+ Don't forget to fit the end cover gasket. Check also
me that the rubber washer and plastic plug are mounted
“| in the cover.
Dy a Place the sims inside the end cover in the same posi-
| Ral tion as prior to removal of the cover, or select a new
al combination of shims. See ‘Transmission case and
end cover’ in this section, Smear a little grease onto
the shims to hold them in the cover, thus facilitating
reassembly.
; fit th ver. If tool 78 40 697 is not available,
HOLDING THE POPPET BALL IN THE REVERSE GEAR SHIFT 6 Biatit § Re < pe we = .
FORK the task is facilitated by sliding one of the forks in
Tool 78 40 697 onto its shaft (engaging one gear), thus assembling
this slightly before or after the other one.
7. Screw in the end cover bolts and tighten with a tor-
que of 25 Nm (18 ft.lb., 2.5 kpm).
3. Drive in the reverse gear shift fork shaft and collect
the tool as it is ejected at the front end of the fork. CAUTION
Make sure that the bolt opposite the reverse gear
shift fork is not too long, thereby impeding the
movement of the fork.
471—20 Febr 1977
Page 413
8. Check the gear shift fork shafts and adjust as neces-
sary, sO that the forks are not subjected to axial
pressure when a gear is engaged. In all gear posi-
tions, there must be a noticeable clearance of the
same magnitude between the synchronizer sleeve
and the respective gear.
9. Place the three gear shift forks at neutral, as well 2
as the shifter yoke and catch in the top cover.
10. Coat the surface of the transmission Case with seal-
SPEEDOMETER DRIVE GEAR
Disassembly and reassembly
1. Disconnect the speedometer drive cable from the trans-
mission case.
. Back off and remove the bearing sleeve (1), together
with the spindle (2) and the speed gear (3). Collect
2 the gasket (5).
ing compound. Then refit the cover and tighten up 3. Drive out the tension pin (4) which holds the speed
the screws. gear to the spindle. The speed gear, spindle and bear-
11. Check the function of the gear shift mechanism. ing sleeve can now be separated.
NOTE
The transmission case is ventilated through the oper-
ating shaft and the hole in the lower side, under the
universal joint for the gear shift rod. Make sure that
this hole is not clogged, since this could lead to oil
leakage at the seals.
SPEEDOMETER DRIVE GEAR
1. Bearing sleeve
2. Spindle wrens
3. Speed gear PO
4. Tension pin i
5. Gasket wi
Change all worn or defective parts and reassemble in the anne
reverse order. we
To prevent oil leakage, the axial spindle clearance should
be between 0.002 and 0.008 in. (0.05—0.2 mm). This
clearance can be adjusted by inserting shims, 0.008 and
0.02 in. (0.2—0.5 mm) thick, between the speed gear and
the bearing sleeve.
{
|
Shimming
SAA 471-21
Febr 1977
Page 415
DIFFERENTIAL AND
pINION/RING GEAR
PINION SHAFT AND RING GEAR
General
The pinion shaft and differential ring gear should be dis-
assembled and reassembled in the manner described in
section 471. The counter shaft must be removed first,
followed by the primary shaft, before the pinion shaft
can be disassembled. The pinion shaft is carried in a roller
bearing and a double row ball bearing which constitutes
the axial bearing. The pinion shaft carries the keyed 3rd
gear wheel, while the 4th gear wheel is press-fitted. The
speed motor drive is located between the gear wheels.
The gears are matched with the corresponding gear wheels
on the primary shaft and in course of assembly care must
be taken to ensure that the matching numbers face the
same way on both pinion shaft and primary shaft.
The ring gear and pinion shaft, too, form a matched set,
implying that these two components can only be changed
as a pair. These parts have been tested together for noise
and the most favourable setting for quiet running has
been measured. Measurements of particular importance
for the pinion and ring gear are the distance between the
end face of the pinion and the center of the ring gear, and
the gearing backlash. These measurements, as well as the
matching numbers, are stamped into the parts concerned
in conjunction with the noise test. When assembling the
pinion and ring gear, these measurements must be adjusted
very accurately with shims and a special measuring tool.
The pinion shims are located by the rear pinion shaft bear-
ing, and the shims for the differential ring gear by both
bearings.
$ 2139
PINION SHAFT WITH BEARINGS AND GEARS, AS FROM CHASSIS NO. 470.001 AND 52.001
S 616
ADJUSTMENT OF DISTANCE BETWEEN PINION END FACE
AND CENTER OF RING GEAR BY SHIMMING THE PINION
SHAFT
The measurement A to be adjusted by shimming the pinion shaft
Febr 1977
‘ean
0.006 in. (0.15 mm)
617
A
GEARING BACKLASH IS ADJUSTED BY SHIMM
DIFFERENTIAL ING THE
The backlash A = 0.006 in. (0.15 mm) is to be adj
ming the differential bearing fisted by shim.
473-1
Page 416
Adjustment of pinion
2 facilitate adjustment of the distance between the pin-
ion and the center of the ring gear, certain data are
stamped into the end face of the pinion,
S 618
THE PINION END FACE
+3 = Measurement for pinion adjustment.
R913 = Matching number, also to be found on ring gear.
0 = Pinion is not displaced, but the pinion shaft is directed
towards the center of the ring gear. All pinions are
marked with an ''0”, and this information has no in-
fluence on the adjustment.
IMPORTANT
Before disassembling the transmission unit, always
measure the relative positions of the pinion and ring
gear, in order to determine whether the adjustment
has possibly been incorrect. If the pinion and ring
gear have been used only for a short mileage (less
than 6000 miles/10.000 km), the unit can be read-
justed. However, after longer mileages, when the
gears will have become worn in at a certain position,
adjustment should be made to agree with the read-
ings obtained prior to disassembly.
Remedys before measuring
During all measurements of the pinion setting, the follow-
ing points must be observed.
1. The pinion shaft end nut must be correctly tightened,
first with a torque of 120 Nm (85 ft.Ib., 12 kpm), then
with a torque of 60 Nm (46 ft.|Ib., 6 kpm).
2. The transmission case end cover must be shimmed,
fitted with its gasket, and its bolts tightened with a
torque of 25 Nm (18 ft.lb.,2.5 kpm). For shimming
of end cover, see section 471.
3. The differential must be removed to allow application
of the measuring tool 78 41 463, which comprises a
jig carrying a dial indicator. A ground gage block is
provided for adjustment of the dial indicator. The
gage block is placed against the setting lugs of the
tool, and the distance between these and the center
of the ring gear is always 60.94 mm. The tool is suit-
able for use in all types of transmission cases, and
therefore has different stops to suit the various dia-
meters of bearing seats.
473—2
Measuring
The dial indicator has two scales, one of which is gradu-
ated counter-clockwise and gives a lower reading when
the measuring point is pressed in. This scale must always
be used.
Place the ground gage block against the two setting lugs
and against the measuring point. Now zero the dial indi-
cator, i.e. both the hands shall point to zero. Then carry
out the measurement as follows: Locate the dial indicator
in one of the measuring tool holes.
ZEROING THE DIAL INDICATOR
1. Measuring tool 78 41 463
2. Dial indicator
3. Gage block
=
sy
5
L TH
7 j Fra ey
ih ;
me |
HOLES FOR FITTING OF DIAL INDICATOR
A = Transmission case of cast iron
B = Transmission case of aluminium
a
|
1. Check the dial indicator so that the hands point at 0.00
when the measuring point rests against the gage block.
2. Locate the measuring tool in the differential bearing
seats with the measuring point in contact with the
ground face of the pinion and take a reading.
Febr 1977
Page 417
So
PLACING OF MEASURING TOOL WHEN MEASURING
3. When the pinion is correctly adjusted, the dial indi-
cator should show the same figure, in hundredths of a
millimeter, as that marked on the pinion, with a per-
missible deviation of + 0.05 mm.
Note that the dial indicator scale which goes counter-
clockwise must be used, i.e. + is counter counter-clock-
wise and — clockwise.
$ 948
EXAMPLE OF DIAL INDICATOR READING WHEN ADJUST-
MENT IS CORRECT
If the pinion is marked —7, the indicating hands should point to
~0.07 mm. From this value a deviation of + 0.05 mm is permis-
sible,
tl
S9A9
EXAMPLE OF DIAL INDICATOR READING WHEN ADJUST-
MENT IS CORRECT
If the pinion is marked +3, the indicating hands should point to
+0.03. From this value a deviation of + 0.05 mm is permissible.
iairiniee SAAB 473-3
Page 418
Shimming
If the measured value deviates from the correct One more
than permitted by the tolerance, the pinion shaft must be
adjusted.
The adjustment is to be made with spacer and shims,
which shall be placed between the rear thrust bearing and
the 2nd- and reverse gear.
When doing this, always place the shims next to the bear-
ing and the spacer against the gear. The spacers are avail-
able in two thicknesses and the shims can be hed in three
different thicknesses. See table. When adjusting, take only
one of the spacers plus maximum three shims in a suit-
able combination. This covers the adjustment range from
3.1 mm up to 4.2 mm with intervals of 0.05 mm.
NOTE! If the gear box is equipped with the new, rear
pinion bearing with split inner ring, the spacer washer
has to be placed next to the bearing.
=
: g
5
1 2 S 5323
ADJUSTMENT OF PINION SHAFT WITH SHIMS AND SPACER
1. Spacer and shims 4. 3rd gear 72 Bolle bearing
2. Ball bearing 5. Speedometer drive 8. Pinion gear
3. Lock ring 6. 4th gear 9. Ring gear
Spacers Shims
Gear box Location Thickness | Spare part | Thickness | Spare part
No. No.
on 78 22 075
3.6 78 22 158
del 1967
sti Pinion shaft between 0.1 78 22 083
thrust bearing and 0.15 78 22 091
gear 0.3 78 22 109
Sal 78 39 533
. ue 3.6 78 39 541
mode
SAAB
473-4
Febr 1977
Page 419
1, Remove the end cover and back off the pinion shaft
end nut.
9, Pull out the pinion shaft axial bearing, using puller
78 41 158. The front press screw can be used to sup-
port the shaft.
2
5)
REMOVING PINION SHAFT BEARING
Tool 78 41 158
3. Remove the spacer and shims.
4. Change the shimming as per the following rules:
If the dial indicator reading was too high, increase the
thickness of the shims combination.
lf the dial indicator reading was too low, reduce the
thickness of the shims combination. Note that + is
counted counter-clockwise and — clockwise. The
amount by which the shimming thickness is to be in-
creased or decreased is the same as the difference be-
tween measured and true values.
5. Having selected the correct combination of shims,
place the spacer, followed by the shims, on the pinion
shaft. Drive the pinion shaft bearing in with tool
78 41 224, using the front press screw to support the
shaft.
C
Ss 6”
sa ANNA
DRIVING IN PINION SHAFT THRUST BEARING
1, Tool 78 41 224
2. Bearing or bearing seat
3. Press screw for supporting the shaft
Febr 1977
6. Fit the retaining ring. Then tighten the pinion shaft
end nut, first with a torque of 120 Nm (85 ft.lb., 12
kpm) and then with 60 Nm (45 ft.Ib., 6 kpm). Secure
the nut, See section
7. Refit the end cover and appurtenant shims. Tighten
the end cover screws with a torque of 25 Nm (18 ft.Ib.,
2.5 kpm).
As from transmission No. F 39522 and 274571 respective-
ly, a new rear pinion bearing with a split inner ring has
been introduced.
This new bearing has to be disassembled in two stages.
The bearing is pulled off the shaft as before with puller
78 41 158, but the inner part of the inner ring now re-
mains on the shaft. It can subsequently be removed with
puller 78 60 521.
The diameter of the spacer has been decreased to simplify
removal of the inner ring.
In reassembling, place the loose inner ring on the shaft,
followed by the main part of the bearing. Then press the
entire bearing into place in the usual manner.
Note that in this version the shims are to be located be-
tween the washer and the gear.
Rechecking
After shimming, refit the measuring jig in the differential
bearing seat and check that the dial indicator gives the
correct reading (+ 0.05 mm). Readjust if necessary.
473-5
ee oat
“Reassembly of transmission unit”.
Page 420
Adjustment of ring gear backlash
During adjustment and measurement of ring gear back-
lash, the pinion shaft end nut must always be tightened
to the correct torque and the end cover must be proper-
ly shimmed and tightened to the correct torque.
To facilitate adjustment of ring gear backlash, certain
data are stamped into the ring gear as per the following:
R39
MARKS ON RING GEAR
R913 = Matching number
0.15 = Ring gear backlash.
Note! If this figure is not given, 0.15 mm applies.
This backlash may be measured at any point.
S 623
Checking the measuring tool
The measuring tool is made with great precision. It should
therefore be handled with great care, in order to avoid
blow marks and/or deformation. If the tool is suspected
damaged, check its measures, sO that reliable results are
obtained when using it. To this effect check the measures
indicated.
~
20,94+0,01
29,94 +0,01
24,94 + 0,01
~
|
"
(60,94)
MEASURES FOR CHECKING THE MEASURING TOOL 78 41 463
Check the backlash at 4 points round the circumference
of the ring gear. The deviation from the indicated value
must not exceed + 0.05 mm. The gear ring backlash can
be adjusted to the correct value with spacers and shims.
There are two different thicknesses of spacers and three
of shims for each bearing, see table. For shimming, use
one of the spacers together with up to three shims in dif-
ferent combinations.
Spacers Shims
Location by diffe- 2 :
rential bearings Thickness Spare part Thickness Spare part
in. (mm) No. in. (mm) No.
Right 0.13 (3.4) 78 24 899 0.004 (0.1) 78 24915
0.15 (3.9) 78 24 907 0.006 (0.15) 78 24 923
0.012 (0.3) 78 24 931
Left 0.13 (3.4) 78 13 918 0.004 (0.1) 78 13 926
0.15 (3.9) 78 22 125 0.006 (0.15) 78 13 983
0.012 (0.3) 78 13 991
473-6
Febr 1977
j