Power Steering Gear Service

DISASSEMBLY

1. Drain gear assembly by rotating stub shaft from stop to stop.

Fig. 2 Removing end cover retaining ring:

2. Rotate cover retainer ring until one end is near hole in side of gear housing and pry ring out.
3. Push end cover out of housing by turning stub shaft counterclockwise. Do not turn stub shaft further than necessary to remove end plug as balls from rack piston will fall and lay loose inside the rack piston chamber.

Fig. 3 Remove rack piston end plug:

4. Remove rack piston end plug. Tap plug as necessary using a hammer and brass drift.
5. Loosen sector shaft adjusting screw locknut.
6. Remove four side cover attaching bolts and lockwashers.
7. Turn side cover until rack piston and sector teeth are visible.
8. Turn stub shaft until sector is centered in housing opening.
9. Remove side cover and sector shaft from housing by tapping end of sector shaft with a rubber mallet.

Fig. 4 Removing rack piston:

10. Install tool No. C-4175 into rack piston bore with pilot of tool seated in end of worm.
11. Turn stub shaft counterclockwise while holding tool tightly against worm forcing the rack piston onto the tool.
12. Remove rack piston from housing, keeping the ball retainer tool in place to hold balls in position.
13. Remove adjuster plug locknut.

Fig. 5 Remove adjuster plug:

14. Remove adjuster plug assembly using spanner wrench. Remove and discard O-ring.
15. While holding stub shaft, pull valve assembly and stub shaft from housing.
16. Remove wormshaft, lower thrust bearing and thrust washers. Remove and discard shaft cap O-ring.

ASSEMBLY

Apply suitable lubricant to all components prior to assembly.

FIg. 6 Exploded view of wormshaft & valve body:

1. Install one thrust washer and thrust bearing, then the other thrust washer over end of the wormshaft. If thrust bearings races are tapered, install tapered surfaces parallel to each other cupped side toward stub shaft.
2. Install lower cap O-ring in valve body until it is seated against lower shaft cap.
3. Align notch in valve body with pin in worm, then install valve and shaft assembly into gear housing. Apply pressure to valve body instead of stub shaft when installing, as pressure applied to stub shaft may force it out of valve body.

FIg. 7 Valve body installation in housing:

4. Valve body is fully seated when oil return hole in housing is uncovered.
5. Install O-ring on adjuster plug.
6. Install adjuster plug assembly in housing until it seats against valve body.
7. Push rack piston with teeth facing sector shaft opening until ball retaining tool contacts wormshaft.
8. Holding ball retaining tool against end of wormshaft, thread rack piston onto worm by rotating stub shaft counterclockwise.
9. Remove ball retaining tool when rack piston is completely threaded on wormshaft.
10. Coat new sector shaft O-ring with grease to hold it in place, then position O-ring in side cover.
11. Move rack piston until teeth are centered in sector shaft opening.
12. Install sector shaft and side cover so sector shaft center tooth is centered with tooth gap at center of rack piston.
13. Install side cover bolts, lockwashers and rack piston plug.
14. Install new housing end cover O-ring, end cover and retaining ring.
15. Adjust wormshaft thrust bearing preload and overcenter preload.