Rack Piston and Worm Shaft Replacement - Off Vehicle 708 Model

Tools Required

J 21552 Rack Piston Arbor

1. Remove the pitman shaft.
2. To remove the side cover; refer to Steering Gear Pitman Shaft and Housing Cover Replacement - Off Vehicle .
3. To remove the steering gear housing end plug (1); refer to Steering Gear Housing Plug Replacement - Off Vehicle .
4. Turn the stub shaft counterclockwise until the rack piston (2) begins to come out of the steering gear housing.
5. Remove the rack piston plug.
6. Insert J 21552 into the bore of the rack piston (2).
7. Hold J 21552 tightly against the worm shaft while turning the stub shaft counterclockwise. Turning the stub shaft forces the rack piston (2) onto J 21552 . The rack piston balls remain in place.



8. Remove the following items as an assembly from the steering gear housing (9):

•	The rack piston (4)

•	The rack piston balls (5)

•

J 21552

9. To remove the valve; refer to Steering Gear Valve Replacement - Off Vehicle .
10. Remove the worm shaft (14).
11. Remove the thrust bearing (12).
12. Remove the flat races (11).
13. Remove J 21552 from the rack piston (4).
14. Remove the rack piston balls (5).
15. Remove the following items from the rack piston (4):

15.1.

The screws (8)

15.2.

The clamp (7)

15.3.

The ball guide (6)

16. Remove the teflon ring (2).
17. Remove the O-ring seal (3).
18. Clean all of the disassembled parts.
19. Inspect all of the disassembled parts for wear.
20. Replace the parts if necessary.

Tools Required

1. Lubricate the following items with power steering fluid while installing to the rack piston (4):

1.1.	The O-ring seal (3)

1.2.	The teflon ring (2)

2. Install the worm shaft (14) to the rack piston (4) outside of the steering gear housing (9).




Important: Reinstall all of the rack piston balls in the rack piston. Improper rack piston ball installation may result in personal injury.

3. Fully seat the worm shaft to the rack piston.
4. Align the worm shaft spiral groove with the rack piston ball return guide hole (1).
5. Lubricate the rack piston balls with power steering fluid.
6. Insert the rack piston balls through the ball return guide hole (1) while turning worm shaft (2) counterclockwise in order to install the rack piston balls into the rack piston.



7. Install the remaining rack piston balls (3) into the ball guide (1) using grease at each end (2) in order to retain the rack piston balls (3).



8. Install the ball guide (5) to the rack piston (4).
9. Install the ball guide clamp (6).
10. Install the screws (7).

Tighten
Tighten the screws (7) to 58 N·m (43 lb in).

11. Insert J 21552 into the bore of the rack piston while turning the worm shaft counterclockwise. The turning of the worm shaft forces the rack piston onto J 21552 . The rack piston balls remain in place.



12. Install the flat races (2) (4) and the thrust bearing (3) onto the worm shaft (1).



13. Install the worm shaft (4) to the steering gear housing (3).
14. To install the valve; refer to Steering Gear Valve Replacement - Off Vehicle .
15. Install the rack piston (2) to the worm shaft (4) from J 21552 , using J 8947 to compress the seals.

Important: Reinstall all of the rack piston balls into the rack piston. Improper rack piston ball installation may result in personal injury.

16. Hold J 21552 tightly against the worm shaft (4).
17. Turn the stub shaft clockwise until the rack piston is seated on the worm shaft.
18. Install the rack piston plug.

Tighten
Tighten the rack piston plug to 150 N·m (111 lb ft).

19. To install the steering gear housing end plug (1); refer to Steering Gear Housing Plug Replacement - Off Vehicle .
20. Install the pitman shaft.
21. To install the side cover; refer to Steering Gear Pitman Shaft and Housing Cover Replacement - Off Vehicle .
22. To adjust the steering gear; refer to Steering Gear Pitman Shaft Over-Center Preload Adjustment - Off Vehicle .