Rack Piston and Worm Shaft Replacement

Power Steering Gear (708):

Power Steering Gear - Legend (708):

^ Tools Required:
- J 8947 Rack Piston Teflon Ring Compressor
- J 21332 Rack Piston Arbor
- Or Equivalent

REMOVE OR DISCONNECT
- Steering gear from vehicle.

DISASSEMBLE
1. Pitman shaft and side cover.
2. Housing end plug.
- Turn stub shaft counterclockwise until the rack piston (26) begins to come out of the housing (20).

Rack Piston:

3. Rack piston plug (27).
- Insert J 21552 into bore of rack piston (26). Hold J 21552 tightly against worm shaft while turning the stub shaft counterclockwise.

Installing The Balls In The Rack Piston:

- The rack piston (26) will be forced onto J 21552 and hold the rack piston balls (25) in place.
4. Rack piston (26), rack piston balls (25), and J 21552 together from housing (20).
5. Valve.
6. Worm shaft (13).
7. Thrust bearing (16) and races (15).
8. J 21552 from rack piston (26).
9. Rack piston balls (25).
10. Screws (21), clamp (22) and ball guide (23).
11. Teflon ring (5).
12. O-ring seal (6).

Clean
- All disassembled parts.

Inspect
- All disassembled parts for wear. Replace if necessary.

ASSEMBLE
1. O-ring seal (6) and teflon ring (5) and lubricate with power steering fluid.
2. Worm shaft (13) to rack piston (26) outside of housing (20).
- Fully seat worm shaft (13) to rack piston (263 and align worm shaft spiral groove with rack piston ball return guide hole.

NOTE: Make sure that all rack piston balls (25) are reinstalled in the rack piston. Improper rack piston ball installation may result in personal injury.

CAUTION: The black rack piston balls are smaller than the silver balls. The black and silver balls must be installed alternately into the rack piston and ball guide to maintain rack piston to worm shaft preload.

- Lubricate rack piston balls (25) with power steering fluid.

Placing Balls In The Ball Return Guide:

3. Rack piston balls (25) to rack piston (26) by inserting through ball return guide hole while turning worm shaft (13) counterclockwise.
4. Remaining rack piston balls (25) to ball guide (23) using grease at each end to retain balls (25).
5. Ball guide (23) to rack piston (26).

CAUTION: Always use the correct fastener In the proper location. When you replace a fastener, use ONLY the exact part number for that application. The manufacturer will call out those fasteners that require a replacement after removal. The manufacturer will also call out the fasteners that require thread lockers or thread sealant. UNLESS OTHERWISE SPECIFIED, do not use supplemental coatings (paints, greases, or other corrosion Inhibitors) on threaded fasteners or fastener pint Interfaces. Generally, such coatings adversely affect the fastener torque and pint clamping force, and may damage the fastener. When you install fasteners, use the correct tightening sequence and specifications. Following these Instructions can help you avoid damage to parts and systems.

6. Ball guide clamp (22) and screws (21).
- Tighten (21) to 58 Nm (43 inch lbs.).
- Insert J 21552 into bore of rack piston (26) while turning worm shaft (13) counterclockwise. The rack piston (26) will be forced onto J 21552 and will hold the rack piston balls (25) in place.
7. Races (15 and 17) and thrust bearing (16) to worm shaft (13).

Worm Shaft And Bearing:

8. Worm shaft (13) to housing (20).
9. Valve.
10. Rack piston (26) to worm shaft (13) from J 21552, using J 8947 to compress seals.
- Hold J 21552 tightly against worm shaft and turn stub shaft clockwise until rack piston (26) is seated on worm shaft (13).

NOTE: Make sure that all rack piston balls (25) are reinstalled in the rack piston. Improper rack piston ball installation may result in personal injury.

11. Rack piston plug (27).
- Tighten (27) to 150 Nm (111 ft. lbs.).
12. Housing end plug.
13. Pitman shaft and side cover.

ADJUST
- Steering gear.

INSTALL OR CONNECT
- Steering gear.