Assembly

NOTE: When installing replacement oil seals lubricate with recommended fluid and ensure absolute cleanliness.

1. Install sector shaft oil seal as follows:





a. Install oil seal (52), lip side first.
b. Install extrusion washer (53).
c. Install dust seal (54), lipped side last.
d. Install circlip (55).

2. Install valve and worm assembly as follows:




a. Reinstall original shims and inner bearing cup (56).
- Use Petroleum Jelly to aid assembly.

NOTE: If original shims are not used, install shims of 0.76 mm thickness.

b. Install inner cage and bearings assembly (57).
c. Install valve and worm assembly (58).
d. Install outer cage and bearings assembly (59).
e. Install outer bearing cup (60).
f. Install new worm adjuster sealing ring.





g. Loosely screw adjuster (62) into casing.
h. Install locknut (63), do not tighten.
i. Turn in worm adjuster until end float is almost eliminated.
- Ensure bearing cages are seated correctly.
j Measure maximum rolling torque of valve and worm assembly, using a torque wrench (65) and spline socket tool No. LRT-57-025 or equivalent.
k Turn in worm adjuster while rotating shaft to increase figure measured in step j. to 0.56 Nm.
l Back off worm adjuster 1/4 turn.
- Turn in worm adjuster to increase reading at step j. by 0.21-0.34 Nm with locknut tight, 100 Nm.
- Use worm adjusting wrench tool No. LRT-57-006 and locknut wrench tool No. LRT-57-028, or equivalent.

3. Install rack and piston as follows:





a. Screw slave bolt (68) into piston to aid assembly.
b. Install piston and rack so piston is 70 mm from outer end of bore.

4. Install sector shaft as follows:
Install sector shaft (70) using seal saver tool No. LRT-57-021,or equivalent.
- Align roller with cut out in casing.
- Push in sector shaft while rotating input shaft to allow sector roller to engage worm.

5. Install rack adjuster as follows:





a. Install rack adjuster and thrust pad (71) to engage rack.
- Back off half turn on adjuster.
b. Loosely install new nylon pad and adjuster set screw (72) assembly.

6. Install sector shaft cover as follows:
a. Install new sealing ring to cover.





b. Align cover (74) with casing.
c. Screw cover assembly (74) fully on to sector shaft adjuster screw (75,76).
d. If necessary back off sector shaft adjuster screw (75,76).
- Tap cover in place to allow cover to joint fully with casing.

NOTE: Before tightening fastenings, rotate input shaft to ensure sector shaft roller is free to move in valve worm. If initial resistance is left, turn adjuster screw approximately two turns in a clockwise direction.

e. Install cover bolts (77).
- Tighten to 75 Nm.

7. Install cylinder cover as follows:





a. Install new square section seal (78) to cover.
b. Remove slave bolt installed at step a. of instruction 3.
- Press cover (79) into cylinder just to clear retainer ring groove.
c. Install retaining ring (80) to groove with one end of ring positioned 12 mm from extractor hole.

8. Adjusting sector shaft

NOTE: Reinstall drop arm and tighten nut sufficiently to ensure that no backlash exists between drop arm and sector shaft.

a. To set worm on center, rotate input shaft to full inner-lock (full right lock for a left hand drive vehicle, full left lock for a right hand drive vehicle).
- Rotate input shaft back towards center two full turns.
b. The box is now on center and can be adjusted.





c. Hold input shaft and rock drop arm to establish backlash is present.
- Continue rocking and slowly turn sector shaft adjusting screw (82,83) clockwise.
- Continue rotating adjuster screw (82,83) until backlash has almost been eliminated.
d. Reinstall locknut (84) and tighten.

NOTE: It is important steering box is centralized before any adjustments are made.

e. Check maximum rolling torque one and a quarter turns either side of center position, using a torque wrench and spline socket (85) tool No. LRT-57-025, or equivalent.
- Rotate adjuster screw to obtain across center torque of 0.34 Nm plus torque figure at one and a quarter turns.
- Tighten adjuster locknut to 60 Nm.

9. Adjust rack adjuster as follows:
a. Turn in rack adjuster (86) to increase figure measured in step e. of instruction 8. by 0.23 - 0~34 Nm.
- The final figure may be less, but must not exceed 1.35 Nm.
b. Lock rack adjuster in position with grub screw (87).
- Tighten to 5 Nm.
10. Check torque peak as follows:

NOTE:
^ With input shaft rotated from lock to lock, rolling torque figures should be greatest across center position and equally disposed about center position.
^ The condition depends on value of shimming installed between valve and worm assembly inner bearing cup and casing.
^ The original shim washer value will give correct torque peak position unless major components have been replaced.





a. With input coupling shaft toward the operator, turn shaft fully counter-clockwise.
b. Check torque figures obtained from lock to lock using torque wrench and spline socket.
c. Check also for equal engagement either side of center.

11. Torque peak adjustments:
a. Note where greatest torque peak figures are recorded relative to steering position.
b. If greatest figures are not recorded across center of travel (steering straight-ahead), adjust as follows:
- If torque peak occurs before center position, add to shim washer value.
- If torque peak occurs after center position, subtract from shim washer value,
c. Refer to Installing valve and worm assembly (instruction 2.) above.
- Shim washers are available as follows: 0.03mm, 0.07mm, 0.12mm and 0.24mm.

NOTE: Adjustment of 0.07mm to shim value will move torque peak area by 1/4 turn on the shaft.

CAUTION: When reshimming valve and worm, extreme caution must be exercised to prevent seal damage during reassembly.

12. Install input shaft oil seal as follows:





a. Install seal (92), lip side first, into housing.
- Use seal saver tool No. LRT-57-016 and seal installer tool No. LRT-57-026, or equivalents.
- Note that seal is installed to a depth of 4.75-5.00 mm from face of box.
b. Secure seal with circlip (93).
c. Smear inner lip of dirt excluder with suitable grease.
- Install dirt excluder (94) using tool No. LRT-57-027, or equivalent.





- When installed correctly outer shoulder of excluder is 4.00-4.50 mm from face of box, dimension X in illustration.
d. Remove drop arm.
- Smear inner lip of dirt excluder with suitable grease and reinstall, ensuring outer lip is flush with casing.
e. With input shaft on center, line up centralizing holes in drop arm and steering box.
f. Install drop arm to steering box using a new tab washer.
- Tighten to 176 Nm, bend over tab.