Overhaul

Steering Gearbox Overhaul

Exploded View





Special Tools Required

- Locknut Wrench 07ZAA-S5A0100
- Driver Handle 07NAD-SR30101
- Cylinder End Seal Remover Attachment 07NAD-SR30200
- Pilot Collar 07GAF-PH70100
- Seal Ring Guide 07ZAG-S5A0200
- Sizing Tool, 22.25 mm 07NAG-SR30900
- Sleeve Seal Guide, 35.9 x 37 mm 07YAG-S2X0100
- Sizing Tool, 36 mm 07ZAG-S5A0100
- Bearing Driver Attachment, 32 x 35 mm 07746-0010100
- Driver Handle, 15 x 135L 07749-0010000
- Piston Seal Ring Guide 07ZAG-S7A0100
- Piston Seal Ring Sizing Tool 07ZAG-S7A0200
- Driver, 27 mm 07ZAF-S5A0100
- Cylinder End Seal Slider, 23 mm 07974-6890801 or 07974-689080A
- Pincers Oetiker 1098, commercially available

NOTE: Refer to the Exploded View as needed during this procedure.

Disassembly

1. Remove the steering gearbox Steering Gearbox Removal, then remove the tie-rod end.

2. Remove cylinder lines (A) and return line joint (B) from the steering gearbox.





3. Drain the fluid from the cylinder fittings by slowly moving the steering rack back and forth.

4. Unbend the lock washers (A).






5. Hold the bracket (A) with a wrench, and unscrew both tie-rods (B) with a wrench. Remove the lock washers.






6. Remove the stop washer (A), the flange bolts (B), O-rings (C), and bracket (D) from the steering gearbox.






7. Remove the boot guard (A) by removing the flange bolt (C) on the rack end.





8. Remove the boot band (D) and clip (E). Pull boot B away from the end of the steering gearbox. Remove the rack end plug (F).

9. Loosen the locknut (A), then remove the rack guide screw (B), spring (C), and rack guide (D) from the gearbox housing.






10. Remove the internal snap ring (A) and backup ring (B) from the cylinder housing.






11. Remove the flange bolts, then remove the valve body unit (A) from the gearbox housing (B). Remove the O-ring (C).






12. Remove the boot bands (B) from boot A. Compress boot A by hand, and wrap vinyl tape (C) so the boots stay collapsed and pulled back.






13. Hold the gearbox housing using a C-clamp (A) and the wooden blocks (B) to a work bench as shown. Do not clamp the cylinder part of the gearbox housing in a vise.






14. Install the locknut wrench (A) on the lock screw (B), then loosen and remove the lock screw from inside of the gearbox housing (C).





15. Remove the locknut wrench.

16. Pull on the cylinder to remove it from the gearbox housing. Remove boot A and the slider guide (B) from the cylinder housing.






17. Check the slider guide for damage and cracks. Use vernier calipers to measure the thickness of the slider guide. If the thickness is less than the service limit (A), replace the slider guide.






18. Remove and discard the stop ring (A) on the cylinder housing by expanding it with snap ring pliers. Remove and discard the lock screw (B).






19. Set the cylinder housing (A) in a press so the cylinder side points downward, then press the cylinder end seal (B) and steering rack (C) out of the cylinder housing. Hold the rack to keep it from falling when pressed clear.





20. Remove the cylinder end seal from the steering rack.

21. Insert a driver handle (A), on the cylinder end seal remover attachment (B) into the cylinder housing. Make sure the cylinder end seal remover attachment is securely positioned on the bushing edges (C).





22. Place the cylinder housing in a press, then remove the cylinder end seal (D), backup ring (E), and bushing (F) from the cylinder housing by pressing on the cylinder end seal remover attachment.

Note the items when pressing the cylinder end seal:

- Keep the tool straight to avoid damaging the cylinder wall. Check the tool angle and correct it if necessary when removing the cylinder end seal.
- Use a press to remove the cylinder end seal. Do not try to remove the seal by striking the tool; striking the tool would break the cylinder end seal, and the seal would remain in the cylinder housing.

23. Carefully pry the piston seal ring (A) and O-ring (B) off the rack piston. Be careful not to damage the inside of the seal ring groove and piston edges when removing the seal ring.






24. Before removing the valve housing (A), wrap vinyl tape (B) over the splines on the pinion shaft.





25. Separate the valve housing from the pinion shaft/valve using a press.

26. With your finger, check the inner wall of the valve housing where the seal ring slides. If there is a step in the wall, the housing is worn, replace it.

NOTE: There may be sliding marks from the seal ring on the wall of the valve housing. Replace the valve housing only if the wall is stepped.






27. Check for wear, burrs, and other damage to the edges of the grooves in the sleeve.

NOTE: The pinion shaft and sleeve are a precision matched set. If either the pinion shaft or sleeve must be replaced, replace both parts as a set.






28. Remove the external snap ring (A) and sleeve (B) from the pinion shaft (C).






29. Using a cutter or an equivalent tool, cut and remove the four seal rings (A) from the sleeve. Be careful not to damage the edges of the sleeve grooves and outer surface when removing the seal rings.






30. Using a cutter or an equivalent tool, cut the valve seal ring (A) and O-ring (B) at the cutting groove position (C) in the pinion shaft. Remove the valve seal ring and O-ring. Be careful not to damage the edges of the pinion shaft groove and outer surface when removing the valve seal ring and O-ring.






31. Remove the valve oil seal (A) and wave washer (B) from the pinion shaft.

Note these items during disassembly:

- Inspect the ball bearing (C) by rotating the outer race slowly. If there is any excessive play or wear, replace the pinion shaft and sleeve as an assembly.
- The pinion shaft and sleeve are a precise fit; do not intermix old and new pinion shafts and sleeves.





32. Remove the valve oil seal (A) and roller bearing (B) out of the valve housing using a hydraulic press and a pilot collar (C).






Reassembly

33. Wrap vinyl tape (A) over the stepped portion of the pinion shaft, and coat the surface of the vinyl tape with power steering fluid.





34. Install the wave washer (B). Coat the inside surface of the new valve oil seal (C) with power steering fluid, and install the seal with its grooved side facing opposite the bearing, then slide it over the pinion shaft, being careful not to damage its sealing lip (D). Remove the vinyl tape.

35. Install the valve seal ring guide (A) over the pinion, and coat the surface of the tool with power steering fluid. Slip the new O-ring (B) and new valve seal ring (C) over the valve seal ring guide, and expand them.





36. Fit the O-ring in the groove of the pinion shaft. Then slide the valve seal ring over the shaft and in the groove on the pinion shaft.

37. Remove the valve seal ring guide, and apply power steering fluid to the surface of the valve seal ring (A).





38. Apply power steering fluid to the inside of the sizing tool (B). Set the larger diameter end of the sizing tool over the valve seal ring, and move the sizing tool up and down several times to make the valve seal ring fit in the pinion shaft groove.

39. Remove the sizing tool, turn it over, and slide the smaller diameter end over the valve seal ring. Move it up and down several times to make sure the valve seal ring fit snugly in the pinion shaft groove.

40. Apply power steering fluid to the surface of the sleeve seal guide (A). Slip two new seal rings (B) over the sleeve seal guide from the smaller diameter end, and expand them. Install only two rings at a time from each end of the pinion shaft sleeve (C).

Note these items when installing the seal rings:

- Do not over-expand the seal rings. Install the resin seal rings with care so as not to damage them. After installation, make sure you contract the seal rings using the sizing tool.
- There are two types of sleeve seal rings; black and brown. Do not mix the different types of seal rings as they are not compatible.





41. Align the ring guide with each groove in the sleeve, and slide a sleeve seal ring into each groove. After installation, compress the seal rings with your fingers temporarily.

42. Apply power steering fluid to the seal rings (A) on the sleeve, and to the entire inside surface of the sizing tool (B), then slowly insert the sleeve into the sizing tool.





43. Move the sleeve back and forth several times to make sure the seal rings fit snugly in the sleeve. Make sure the seal rings are not twisted and contract the seal rings.

44. Apply power steering fluid to the surface of the pinion shaft (A). Slide the sleeve (B) onto the pinion shaft by aligning the locating pin (C) on the inside of the sleeve with the cutout (D) in the shaft. Then install the new external snap ring (E) securely in the pinion shaft groove. Be careful not to damage the valve seal ring when inserting the sleeve.






45. Apply power steering fluid to the seal ring lip of the new valve oil seal (A), then install the seal in the valve housing (B) using a hydraulic press, driver handle (C), and attachment (D). Install the seal with its grooved side facing the tool.





46. Press the roller bearing (E) into the valve housing with a hydraulic press, driver handle, and attachment.

47. Wrap vinyl tape (A) over the pinion shaft, then coat the vinyl tape with power steering fluid.





48. Insert the pinion shaft into the valve housing (B). Be careful not to damage the valve seal rings (C) and valve oil seal sealing lip (D).

49. Remove the vinyl tape from the pinion shaft, then remove any residue of the tape adhesive.

50. Press the pinion shaft/sleeve into the valve housing with a hydraulic press. Check that the pinion shaft/sleeve turns smoothly by hand after installing it.





51. Coat the piston seal ring guide with power steering fluid, then slide it onto the rack, big end first.

52. Position the new O-ring (A) and new piston seal ring (B) on the piston seal ring guide (C), then slide them down toward the big end of the tool.

Note these items during reassembly:

- Do not over expand the resin seal ring. Install the resin seal ring with care so as not to damage them. After installation, make sure you contract the seal ring using the piston seal ring sizing tool.
- Replace piston's O-ring and seal ring as a set.





53. Pull the O-ring off into the piston groove, then pull the piston seal ring off into the piston groove on top of the O-ring.

54. Coat the piston seal ring (A) and the inside of the piston seal ring sizing tool (B) with power steering fluid, then carefully slide the tool onto the rack and over the piston seal ring.





55. Move the sizing tool back and forth several times to make the piston seal ring fit snugly in the piston.

56. Set the new bushing (A) on the driver (B), and insert the driver and driver handle (C) into the cylinder housing (D).





57. Set the cylinder in a press, and install the bushing into the bottom of the cylinder housing by pressing on the tool with a press. Do not push on the tool with excessive force as it may damage the new bushing.

58. Coat the sliding surface of the cylinder end seal slider (A) and new cylinder end seal (B) with power steering fluid. Place the seal on the seal slider with its grooved side (C) facing opposite the seal slider.





59. Apply a thin coat of power steering grease to the inside of the seal slider.

60. Install the new cylinder end seal (A) onto the steering rack (B) with its grooved side (C) toward the piston (D). Make sure the gap in the cylinder end seal slider (E) is opposite of rack teeth.






61. Separate the cylinder end seal from the cylinder end seal slider (A), then remove the seal slider.






62. Install the backup ring (A) on the steering rack, then place the backup ring and cylinder end seal (B) against the piston (C).






63. Mark (A) a position on the steering rack surface with a felt-tip marker, 7.7 mm (0.3 in) from the rack end.






64. Apply steering grease to the steering rack teeth, then insert the steering rack (A) into the cylinder housing (B). Be careful not to damage the inner surface of the cylinder wall and bushing with the rack edges.






65. Set the cylinder housing (A) in a press, then press the cylinder end seal (B) into the bottom of the cylinder housing until the mark (C) on the rack meets the edges (D) of the cylinder housing.






66. Coat the inside and outside surfaces of the new cylinder end seal (A) with power steering fluid.





67. Install the cylinder end seal onto the steering rack (B) with its grooved side (C) toward the piston. Push in the cylinder end seal with your finger.

68. Place the backup ring (D) on the cylinder end seal with its flat side facing upward. Then drive the backup ring in with the appropriate size socket until the its surface is below the internal snap ring groove (E). Install the internal snap ring (F) in the groove.

69. Install the new lock screw (A) on the cylinder housing.





70. Install the new stop ring (B) in the groove (C) on the cylinder housing by expanding it with snap ring pliers. Be careful not to scratch or damage the cylinder surface with the stop ring edges.

71. Coat the cylinder housing surface with multipurpose grease as shown.






72. Set the new boot bands (B) on the band installation grooves of boot A by aligning the tabs (C) with the holes (D) of the band. Do not close the ear portion of the boot band yet.





73. Compress boot A by hand, and wrap vinyl tape (E) over the bellows so the boots stay collapsed and pulled back. Slide boot A over the cylinder housing so the smaller diameter end of the boot faces the gearbox housing.

74. Apply steering grease to the sliding surface of the slider guide (A). Keep grease off of the rack-to-slider guide matching surfaces and the boot-to-slider guide matching surfaces. Slide the steering rack all the way to left, and place the slider guide on the steering rack by aligning the bolt holes (B).






75. Hold the gearbox housing using a C-clamp (A) and the wooden block (B) to a work bench as shown. Do not clamp the gearbox housing in a vice.






76. Push the cylinder housing (A) into the gearbox housing (B) so the notch (C) is aligned with the pin (D) inside of the gearbox housing.






77. Tighten the lock screw (A) by hand first, then install the locknut wrench (B) on the lock screw. Lightly tighten the lock screw. Do not tighten the lock screw to the specified torque yet.





78. Remove the locknut wrench.

79. Coat the new O-ring (A) with steering grease, and carefully fit it on the valve housing.





80. Apply steering grease to the needle bearing (B) in the gearbox housing, then install the valve body unit (C) by engaging the gears. Note the valve body unit installation position (direction of the line connections). Tighten the flange bolts (D) to the specified torque.

81. Apply steering grease to the sliding surface and circumference of the rack guide (A), and install it into the gearbox housing. Wipe the grease off the threaded section of the gearbox housing.





82. Remove the old sealant from the rack guide screw (B), then apply new sealant (Three Bond 1215 or Loctite 5699) to the middle of the threads. Install the spring (C), rack guide screw, and locknut (D).

NOTE: If more than 5 minutes have passed after applying the sealant, remove the old sealant and residue, and reapply new sealant.

83. Adjust the rack guide screw Adjustments. After adjusting, check that the rack moves smoothly by sliding it right and left.

84. Center the steering rack within its stroke, and align the slider guide (B) with the holes (C) in boot A. Fit the slider guide to boot A by pressing around the edges of the holes securely.





85. Before installing the bracket (D), clean the mating surfaces between the flange bolts (E) and bracket. Coat the new O-rings (F) with power steering grease, and install them on the flange bolts.

86. Loosely install the bracket on the steering rack by tightening the flange bolts to 25 Nm (2.5 kg-m, 18 lb-ft).

87. Hold the gearbox housing using a C-clamp, then install the locknut wrench (A) on the lock screw (B). Retighten the lock screw to the specified torque. Remove the locknut wrench.






88. Retighten the flange bolts (A) to the specified torque.





89. After tightening the flange bolts, install a new stop washer (B) over one of the bolt heads (C). Be sure the tabs (D) of the stop washer are aligned with the flat surfaces (E) of the bolt head.

90. Clean off any grease or contamination from the boot installation grooves around the housing.

91. Expand boot A by removing the vinyl tape, and fit the boot ends (B) in the installation grooves on the cylinder housing.






92. Close the ear portion (A) of the bands with a pincers oetiker 1098, commercially available or equivalent (B).






93. Install the rack end plug (A). Clean off any grease or contamination from the boot installation grooves (C) around the housing and the rack end plug.





94. Slide the steering rack, and adjust the distance between the cylinder housing end and the end of the rack end plug to 70.5 mm (2.8 in). Install boot B, and set the boot end in the installation grooves in the cylinder housing and the rack end plug properly. Install the clip (D) and boot guard (E). Install the new boot band (F) in the band grooves of boot B by aligning the tabs (G) with the holes (H) in the band.

95. Close the ear portion (A) of the band with a pincers oetiker 1098, commercially available or equivalent (B). Slide the rack right and left to be certain that the boots are not deformed or twisted.






96. Install a new lock washer (A) on the tie-rod (B) with the reduced side of the washer toward the tie-rod, and screw the tie-rod into the bracket (C). Repeat this step for the other tie-rod. Hold the bracket with one wrench, and tighten both tie-rods to the specified torque with another wrench.






97. Bend the lock washers (A) against the flat spots on the bracket with a large pair of pliers.






98. Install the cylinder lines (A) and return line joint (B).

Note these items during reassembly:

- Thoroughly clean the joints of the cylinder lines. The joints must be free of foreign material.
- Install the cylinder lines by tightening the flare nuts by hand first, then tighten the flare nuts to the specified torque.





99. Install the tie-rod end, then install the steering gearbox Steering Gearbox Installation.