Page 31
))
644-14 Power-assisted steering system
17 Remove the circlip from inside the pinion
housing.
18 Tap out the lower pinion bearing.
19 Tap out the bush and seal using a drift.
Page 32
nn, La i
Power-assisted steering system 644-15
To assemble
1 Fit the bush with the aid of tool 89 96 407.
2 Tap inthe seal, with the chamfered side up-
permost.
H
w! 3 Tap in the lower pinion bearing using a suit-
able socket (e.g. 19 mm) as a drift.
Page 33
644-16 Power-assisted steering system
4 Fit the circlip.
5 Inspect the condition of the piston ring on
the rack.
N.B.
Two piston variants are in use: one fitted with
piston ring 8937070 alone; and the other with
both a piston ring (89 70873) and an "O” ring
{89 70 865).
As from date code 6 A052 on the steering gear,
the piston must be fitted with both a piston ring
(89 70873) and an "O"ring (89 70865). The
date code is stamped on the damping yoke ad-
justing screw; the first digit denotes the year of
manufacture, and the last three digits the day of
manufacture.
Pistons requiring both a piston ring and an
"O"ring also carry a groove adjacent to the
groove for the piston ring.
Neither the piston rings nor the "O" ring are inter-
changeable.
6 Slide the inner hydraulic seal onto the rack
followed by the plastic end stop. Use tool
89 95 946 to prevent the rubber seal being
damaged by the teeth on the rack.
$6152
$6450
> 6AS3
Saab 900
Page 34
Power-assisted steering system 644-17
7 Press the rack into the housing, using a 17-
mm socket and a short extension piece be-
tween the press and the rack, and tool
83 90 148 (special tool for section 4 - gear-
box) as a support.
Maximum pressing force:
2,200 N (506 Ibf)
» 8 Fit a new "O” ring onto the outer seal re-
tainer. Inspect the seal itself; if it is in good
condition it can be refitted. If a new seal is
required, use tool 89 96 407 to fit it.
9 Fit the bush (1) on the rack, with the nar-
rower end inwards.
10 Slide the wave spring washer (2) up to the
bush and then fit the hydraulic seal (3). Take
care not to damage the sealing lip.
Page 35
644-18 Power-assisted steering system
11 Carefully drive in the seal retainer using tool
83 90 148 (special tool for section 4 - gear-
box).
| 12 Centre the rack and rotate it to enable it to
mesh with the pinion.
13 Fitnew seals on the valve. Remove any burrs
on the splines as these can damage the dust
seal.
Inspect the four PTFE rings on the valve to
see whether they are split. If not, use a razor
' blade to make a 5-7-mm long slit through
each ring. Cut the slits by applying pressure
- do not saw,
The slits serve to compensate for the loss of
power assistance that can occur im-
mediately after starting at low ambient
temperatures.
14 Fitthe servo valve and pinion unit as follows:
¢ Hold the valve body with the slot in the
end of the shaft pointing to the left (at
9o'clock looking towards the front of the
car - see "A” in picture) as the teeth are
enmeshed.
3 e Slide the valve unit in as far as it will go
and then tap it home using sleeve
7841067 (special tool for section 4 -
gearbox). The pinion should now be ro-
tated so that the slot in the end of the
shaft will be in the 12 0’clock position (B
in picture) when the rack is centred.
Saab 900 j
Page 36
re TS i |
Power-assisted steering system 644-19
e Fit the circlip.
ww! 15 Fit and tighten the locknut on the pinion
shaft, using water pump pliers to grip the
other end of the shaft.
Tightening torque:
| w! 30 - 45 Nm (22.2 - 33.3 Ibf ft)
using sleeve 78 41 067 (special tool for sec-
fw! 16 Fit the bottom end cap by tapping it home
| tion 4 - gearbox).
Saab 900
Page 37
|] a
644-20 Power-assisted steering system
17 Apply grease to the damper yoke and then fit
the yoke, followed by the spring, adjusting
screw and locknut.
Lubricant: Shell EP B2 lithium grease (code
71303), Shell Retinax A or the equivalent.
Ee
Adjust the radial! pressure on the rack as fol-
lows:
® Screw the adjusting screw right home.
® Back off the adjusting screw by between
40° and 60°.
e Tighten the locknut.
Tightening torque:
60 - 90 Nm (44.4 - 66.6 Ibf ft)
Saab 900
Page 38
Power-assisted steering system 644-21
18 Fitthe inner ball joint complete with end stop
onto the pinion end of the rack. Mount the
rack housing in a soft-jaw vice.
N.B.
Under no circumstances hold the pinion when
undoing or tightening the ball joint.
e When refitting the old ball joint, a special
ww spacer, part no. 89 46 360, must be fit-
ted to offset the old peening marks by
90°.
w)
19 Tighten the ball joint using tool 8996 480
and a torque wrench.
Tightening torque:
80 - 100 Nm (59.2 - 74.0 Ibf ft)
Lock the ball joint to the rack by driving the
tab into the groove in the rack.
Old peening mark offset by 90°
S$ 6/63
Saab 900
Page 39
Oc
644-22 Power-assisted steering system
20 Move the rack to the end of its travel at the
opposite end to the pinion.
21 Fitthe circlip inside the end of the rack hous-
ing as follows:
e Mount the rack housing in a soft-jaw vice.
Slide sleeve 89 96 407 onto the rack and
press in the spring-loaded seal retainer
by screwing on the inner ball joint.
e Fit the circlip.
N.B.
To enable the circlip to be removed again in the
future, one end of the circlip must be directly in
line with the hole in the rack housing.
e Remove sleeve 89 96 407.
22 With the rack again mounted in a soft-jaw
vice, fit the inner ball joint and end stop
i using tool 89 96 480 and a torque wrench.
e When refitting the old ball joint, a special
spacer, part no. 8946360, must be fit-
ted to offset the old peening marks by
90°.
Tightening torque:
80 - 100 Nm (59.2 - 74.0 Ibf ft)
Lock the ball joint to the rack by driving the
it tab into the groove in the rack.
23 Refit the rubber gaiters complete with pres-
sure-equalizing capillary tube and secure
the clips.
Page 40
Power-assisted steering system
1 Rack housing
2 Rack with piston
3a Piston ring
3b "0" ring
4a Pinion
4b Control valve
5 Hydraulic seal
6 Bush
7 Wave spring washer
8 Seal retainer
9 "O" ring
10 Circlip
11 Needle bearing and race
12 Ball bearing
13 Locknut
14 Endcap
15 Dust cap
16 Damper yoke
18 Adjusting screw
19 Thrust washer (end stop)
20 Inner ball joint and track rod assembly
21 Rubber gaiter
22 Track-rod end
24 Shim (on reassembly)
25 Rubber bush