Lexus GS, SC 1998-06

Removal & Installation

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  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Front wheels
     

  4.  
  5. Matchmark the steering column universal joint to the control valve shaft.

    Click image to see an enlarged view

    Fig. Matchmarking the intermediate shaft to the control valve shaft-GS300, GS400, GS430

  6.  
  7. Loosen the upper bolt and remove the lower bolt to the intermediate shaft universal joint.
  8.  
  9. Remove or disconnect the following:

    Intermediate shaft from the control valve shaft.
     
    Tie rod ends from the steering knuckle.
     
    Fluid lines from the rack and pinion and cap the lines.
     
    2 tube clamps by removing the bolt.
     
    Mounting bolts and nuts. Remove the rack and pinion.
     

  10.  

To install:

  1. Center the rack and pinion to the following dimensions:

    Dimension A : 1.14 in. (28.9mm)
     
    Dimension B : 23.54 in. (589mm)

    Click image to see an enlarged view

    Fig. Centering the rack and pinion-GS300, GS400, GS430

     

  2.  
  3. Install or connect the following:

    Rack and tighten the bolts to 72 ft. lbs. (98 Nm).
     
    2 tube clamps and tighten the bolt to 12 ft. lbs. (17 Nm).
     

  4.  
  5. Align the matchmarks on the intermediate shaft and control valve shaft. Tighten the intermediate shaft bolts to 26 ft. lbs. (35 Nm).
  6.  
  7. Install or connect the following:

    Fluid lines to the rack and pinion with new washers. Tighten the union bolts to 36 ft. lbs. (49 Nm).
     
    Tie rod ends
     
    Wheels
     
    Negative battery cable.
     

  8.  
  9. Lower the vehicle.
  10.  
  11. Check the steering wheel center point.
  12.  
  13. Check the front wheel alignment.
  14.  

  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
  2.  
  3. Place the front wheels facing straight ahead.
  4.  
  5. Remove or disconnect the following:
    CAUTION
    Keep the upper surface of the wheel pad pointed away from you at all times. Store the pad with the upper surface facing upward.



    Negative battery cable. Wait at least 90 seconds before performing any work.
     
    Steering wheel pad
     



    Intermediate shaft
     
    Right and left tie rod ends
     
    Union bolt and gasket and remove the pressure tube
     
    Union bolt and 2 gaskets; remove the return tube
     
    PPS solenoid connector
     
    On SC400 models, the tube clamp
     
    2 bolts and nuts and remove the bracket and grommet
     
    2 bolts and nuts; remove the rack and pinion assembly
     

  6.  

To install:

  1. Install or connect the following:

    Rack and pinion assembly with the 2 set bolts and nuts. Tighten the bolts to 56 ft. lbs. (76 Nm).
     
    Bracket and grommet with the 2 bolts and nuts. Tighten the bolts to 56 ft. lbs. (76 Nm).
     
    On SC400 models, the tube clamp
     
    PPS solenoid
     
    Return tube with the bolt and new gaskets. Tighten the union bolt to 36 ft. lbs. (49 Nm).
     
    Pressure tube with the union bolt and a new gasket. Tighten the union bolt to 36 ft. lbs. (49 Nm).
     
    Right and left tie rod ends
     
    Intermediate shaft
     
    The steering wheel. Tighten the steering wheel set nut to 26 ft. lbs. (35 Nm).
     
    Steering wheel pad
     
    Negative battery cable
     
    Steering fluid and bleed the steering system.
     

  2.  

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Set front wheels in straight-ahead position, then remove the front wheels.
  4.  
  5. Disconnect the negative battery cable and wait for at least 90 seconds before proceeding.
  6.  
  7. Remove the steering wheel pad:
    1. Remove the 2 lower steering wheel covers or the No. 2 cover and the pad switch modulator cover (4.3L).
    2.  
    3. Loose the Torx®head bolts on either side of the steering wheel until the grooves along the bolt circumference catches on the bolt case.
    4.  
    5. Pull the wheel pad out and disconnect the airbag connector. Store the airbag face up and in a safe place.
    6.  

  8.  
  9. Remove the steering wheel:
    1. Disconnect the wiring connector.
    2.  
    3. Remove the steering wheel set nut.
    4.  
    5. Make matchmarks across steering wheel and main shaft assembly.
    6.  

  10.  
  11. Disconnect the left and right tie rod ends, placing matchmarks on screw portion for proper reinstallation.
  12.  
  13. Disconnect the intermediate shaft assembly after making matchmarks as shown.
  14.  
  15. Remove the front suspension member brace.
  16.  
  17. Disconnect the pressure feed and return power steering pipes.
  18.  
  19. Disconnect the tube clamp(s).
  20.  
  21. Remove the bolts and remove the power steering gear assembly.

    Click image to see an enlarged view

    Fig. Matchmarking the intermediate shaft to the control valve shaft-GS 300 and GS 430

  22.  

To install:

  1. Center the rack and pinion gear assembly as shown.

    Click image to see an enlarged view

    Fig. Centering the rack and pinion-GS 300 and GS 430

  2.  
  3. Install the steering gear assembly to its mounting position. Install and torque the bolts as follows:

    2000-03: 72 ft. lbs. (98 Nm)
     
    2004-06: 48 ft. lbs. (65 Nm)
     

  4.  
  5. Reconnect the tube clamp(s); torque tube clamps and tighten the bolt to 12 ft. lbs. (17 Nm).
  6.  
  7. Connect the steering gear to the intermediate shaft assembly and torque the bolts above and below the U-joint to 26 ft. lbs. (35 Nm).
  8.  
  9. Reconnect the pressure feed tube and the return tube, with a new gasket on the union bolts. Torque the bolts to 36 ft. lbs. (49 Nm).
  10.  
  11. Reconnect the tie rod ends, installing them to their original positions as marked.
  12.  
  13. Install the front wheels and position them in a straight-ahead position.
  14.  
  15. Install and center the spiral cable:
    1. Turn the spiral cable counterclockwise by hand until it becomes hard to turn.
    2.  
    3. Then, rotate the cable clockwise about 3 turns to align the marks at the bottom of the assembly.
    4.  

  16.  
  17. Install the steering wheel, aligning the matchmarks made during removal. Temporarily install and tighten the wheel set nut. Connect the connector.
  18.  
  19. Bleed the power steering system.
  20.  
  21. Check the steering wheel center point; if okay, torque the wheel set nut to 37 ft. lbs. (50 Nm).
  22.  
  23. Install the steering wheel pad:
    1. Connect the airbag connector.
    2.  
    3. Install the pad, after confirming that the circumference groove of the Torx bolts is caught on the screw case. Then, torque the Torx bolts to 78 inch lbs. (8.8 Nm).
    4.  
    5. Install the lower steering wheel covers.
    6.  

  24.  
  25. Reconnect the negative battery cable.
  26.  
  27. Check the front wheel alignment.
  28.  



Click image to see an enlarged view

Fig. Power steering gear and related components.-SC 300 and SC 400

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Set front wheels in straight-ahead position, then remove the front wheels.
  4.  
  5. Disconnect the negative battery cable and wait for at least 90 seconds before proceeding.
  6.  
  7. Remove the steering wheel pad.
  8.  
  9. Remove the steering wheel.
  10.  
  11. Disconnect the intermediate shaft assembly after matchmarking the position.
  12.  
  13. Disconnect the left and right tie rod ends, placing matchmarks on screw portion for proper reinstallation.
  14.  
  15. Remove the union bolt and gasket, then disconnect the pressed feed tube.
  16.  
  17. Remove the union bolt and 2 gaskets.
  18.  
  19. Remove the union bolt and 2 gaskets, then disconnect the return tube.
  20.  
  21. Disconnect the PPS solenoid connector.
  22.  
  23. On the SC 400, remove the bolt and disconnect the tube clamp.
  24.  
  25. Remove the 2 bolts, the nuts, bracket and grommet..
  26.  
  27. Remove the 2 bolts, the nuts and the power steering gear..
  28.  

To install:

  1. Install the power steering gear and tighten the 2 gear assembly set bolts and nuts to 56 ft. lbs. (76 Nm).
  2.  
  3. Install the bracket and grommet. Tighten the 2 bolts and nuts to 56 ft. lbs. (76 Nm).
  4.  
  5. On the SC 400, connect the tube clamp and tighten the bolt.
  6.  
  7. Disconnect the PPS solenoid connector.
  8.  
  9. Connect the return tube. Torque the union bolt with a new gasket on each side of the tube to 36 ft. lbs. (49 Nm).
  10.  
  11. Connect the pressure feed tube. Torque the union bolt with a new gasket to 36 ft. lbs. (49 Nm).
  12.  
  13. Reconnect the tie rod ends, installing them to their original positions as marked.
  14.  
  15. Connect the intermediate shaft.
  16.  
  17. Set front wheels in straight-ahead position. Do it with the front of the vehicle jacked up.
  18.  
  19. Center the spiral cable.
  20.  
  21. Install the steering wheel.
  22.  
  23. Bleed the power steering system.
  24.  
  25. Install the steering wheel pad.
  26.  
  27. Install the steering
  28.  
  29. Inspect the front wheel alignment.
  30.  



Click image to see an enlarged view

Fig. Exploded view power steering gear assembly-SC 430

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Place the front wheels facing straight ahead.
  4.  
  5. Remove or disconnect the following:

    Negative battery cable. Wait at least 90 seconds before performing any work.
     
    Front wheels
     
    Steering wheel switch & volume case
     
    Steering wheel pad
     
    Steering wheel column lower cover
     
    Horn button
     
    Steering wheel
     
    Brake caliper
     
    Tie rods from lower ball joint
     
    Engine under cover
     
    Front suspension member braces
     
    Steering slide yoke. Match-mark with control valve shaft before removal
     
    Oil feed tubes
     

  6.  
  7. Remove Rack & Pinion Assembly
  8.  
  9. Remove or disconnect the following:

    Tube clamps on rack assembly
     
    Connector assembly
     
    4 gear assembly set bolts
     
    Steering gear
     
    Steering rack housing bracket
     

  10.  
  11. Match-mark and remove tie rod assemblies
  12.  

To install:

  1. Install or connect the following:

    Tie rod assemblies. Align match marks
     
    Oil feed tubes
     
    Rack & Pinion gear assembly with 4 set bolts; torque to 48 ft. lbs (65 Nm)
     
    Steering sliding yoke assembly
     
    Pressure and return tubes
     
    Tie rod assemblies to lower ball joint; torque to 64 ft. lbs. (87 Nm)
     
    Brake calipers
     
    Front suspension member braces
     
    Engine under cover
     
    Center spiral cable
     
    Temporarily tighten steering wheel assembly
     
    Center steering wheel and fully tighten set nut
     
    Horn button
     
    Steering wheel covers
     
    Steering pad modulator switch
     
    Negative battery cable
     
    Bleed power steering system
     
    Front wheels
     

  2.  
  3. Inspect toe in and adjust as necessary
  4.  
  5. Test drive
  6.  

 
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