Disassembly/Assembly

IMPORTANT The highest regard for cleanliness must always be observed when working with hydraulic components.





DISASSEMBLY.
1. Remove the rubber gaiters.
2. Remove the cable tie, clip and capillary tube.
3. Remove the delivery and return pipes and plug the openings in the control valve casing.
4. Remove the inner ball joint furthest from the pinion as follows:
^ Clamp the rack in a soft jaw vice.
^ Tap down the thrust washer.
^ Using the special tool 89 96 480, unscrew the inner ball joint and remove the thrust washer.

IMPORTANT The pinion should absolutely not be used as a counter grip when tightening or slackening the ball joint.

5. Using a small drift, press down on the end of the circlip inside the rack housing and withdraw the clip by means of a pair of pliers or a hook made of piano wire.





6. Remove the inner ball joint (nearest to pinion) according to the following:
^ Clamp the rack in a soft jaw vice.
^ Tap down the thrust washer.
^ Using tool 89 96 480, unscrew the inner ball joint.
7. Undo the adjusting screw locknut.
8. Remove the adjusting screw, locknut and feather.
9. Lift out the damper yoke. If it proves obstinate, tap the housing gently on the workbench.





10. Knock off the end cap.
11. Remove the locknut. Use an adjustable spanner on the flats to hold the pinion shaft.
12. Remove the dust cap circlip at the upper end of the valve.
13. Press out the servo valve together with the seals and bearings. Use special tool Nos. 83 91 849 and ring No. 87 904 as a counter grip.
14. Withdraw the rack.
15. Remove the outer hydraulic seal retainer (1) and the bush (2).





16. Remove the inner hydraulic seal. Use special tool 89 96 399 and a long drift.
17. Remove the circlip from the valve body.
18. Tap out the lower pinion bearing.
19. Tap out the bush and seal using a drift.





ASSEMBLY
Before assembly the steering system should be oiled and lubricated according to the following:
^ Lubricate the pinion, rack teeth, bearing and seal with 6O grams (ca 7 cl) of lithium grease (Shell EP B2 code 71303, Shell Retinax, or similar.
^ Lubricate the hydraulic components with Saginaw hydraulic fluid, Saab Power Steering Fluid 4634 part No. (45) 30 09 800, or similar.
1. Fit the bush, using tool 89 96 407.
2. Tap in the seal ring with the chamfered side upwards.
3. Tap in the lower pinion bearing by means of a 19 mm socket.
4. Fit the circlip.

NOTE: It is important that the circlip is mounted with its tapered side downwards.

IMPORTANT Note that the lugs on the circlip are not identical. This is to ensure that the circlip will be fitted in the correct position on assembly.

5. Inspect the condition of the piston seal on the rack.

IMPORTANT Two piston seal variants are in use, one comprising piston ring 89 37 070 only and one comprising both piston ring 89 70 87 3 and O-ring 89 70 865.
As of date code 6A O66 on the steering gear, the piston must be fitted with both piston ring 89 70 873 and O-ring 89 70 865. The date code is stamped on the damping yoke adjusting 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 have a groove adjacent to the piston seal.
The two piston seal variants are not interchangeable with piston seals from other units.





6. Slide the inner hydraulic seal onto the rack. First the rubber seal, then the plastic ring. Use tool 89 95 946 to prevent the rubber seal being damaged by the teeth on the rack.
7. Insert the rack into the housing.
8. Press the rack into the housing, using a 7 mm socket and a short extension piece. Use tool No. 83 90148 (special tool) as a support.
Maximum pressure force: 2200 N (506 lbs.)
9. Fit a new O-ring on the outer seal retainer.

NOTE: Inspect the seal. New seal are fitted with tool 89 96 407.

10. Slide the bush (1) and the outer seal retainer (2) onto the rack.
11. Center the rack and rotate it to bring its teeth into mesh with those on the pinion.
12. Fit the needle bearing and seal onto the valve. Press the control valve as follows:
^ Hold the valve body with the slot in the end of the shaft pointing diagonally up to the left (1 o'clock) as the teeth mesh with each other.
^ Slide in the valve as far as it will go and then tap it home using sleeve 78 41 067 (special tool). The pinion should now be rotated to bring the slot in the end of the shaft to the "12 o'clock" position when the rack is centered.
^ centered circlip.





13. Fit and tighten the locknut on the pinion shaft, using an adjustable spanner to grip the other end of the shaft.
Tightening torques: 30 Nm (22 ft. lbs.)
14. Fit the end cap by tapping it home using special sleeve tool No. 78 41 067.
15. Apply grease to the damper yoke and then fit it to the spring, adjusting the screw and locknut.
Lubricant: lithium grease such as Shell EP B2 code 71303, Shell Retinax A, or the equivalent.
16. Adjust the radial pressure as follows:
^ Centre the rack.
^ Tighten the adjusting screw.
Tightening torques: 11 Nm (8 ft. lbs.)
^ Back off the adjusting screw through 40 - 60°
^ Tighten up the locknut to 75 Nm (55 ft. lbs.)
17. Move the rack to the end of its travel in the direction of the pinion.
18. Clamp the rack housing in a soft jaw vice. Screw on the inner ball joint complete with end stop. When refitting the ball joint, a special spacer washer, part No. 89 46 360, must be fitted so that the old peening marks are offset by 90°.





19. Tighten the inner ball joint using tool 89 96 480.
Tightening torques: 90 Nm (67 ft. lbs.)

IMPORTANT: The pinion should absolutely not be used as a counter grip when tightening or slackening the ball joint.

20. Lock the inner ball joint by tapping down the tabs onto the two flats of the rack. Push the end stop into position.
21. Fit the circlip in the end of the rack housing.

IMPORTANT To enable the circlip to be removed again in the future, one end must be directly in line with the hole in the rack housing.

22. Screw the inner ball joint complete with end stop on the other end of the rack housing. When refitting the ball joint, special spacer washer, part no. 89 46 360, is fitted so the old peening marks are offset by 90°.





23. Clamp the rack in a soft jaw vice and tighten the inner ball joint using tool 89 96 480, or equivalent.
Tightening torques: 90 Nm (67 ft. lbs.)

IMPORTANT The pinion should absolutely not be used as a counter grip when tightening or slackening the ball joint.

24. Lock the inner ball joint by tapping down the tabs onto the two flats of the rack. Push the end stop into position.
25. Refit the rubber gaiters and secure the capillary tubes with a cable tie.
26. Reconnect the flow and return pipes and fit the clamp.
27. Screw on the locknuts to the same distance as that measured before their removal.
Tightening torques: 90 Nm (67 ft. lbs.)

IMPORTANT: The pinion should absolutely not be used as a counter grip when tightening or slackening the ball joint.

24. Lock the inner ball joint by tapping down the tabs onto the two flats of the rack. Push the end stop into position.
25. Refit the rubber gaiters and secure the capillary tubes with a cable tie.
26. Reconnect the flow and return pipes and fit the clamp.
27. Screw on the locknuts to the same distance as that measured before their removal.