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Home >> Cadillac >> 2017 >> CT6 Plug-In >> Repair and Diagnosis >> Steering >> Power Steering System >> Repair Instructions >> Power Steering Assist Motor Replacement >> Installation Procedure
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Installation Procedure

  1. Use a clean shop rag to clean the power steering assist motor mating surface on the steering gear housing so it is free of old grease and loose particles.
  2. Install a NEW power steering assist motor seal (1).
    Fig 1: Power Steering Assist Motor And O Ring
    GM3448421Courtesy of GENERAL MOTORS COMPANY
  3. Add a light film of lithium grease to the nose (2) of the power steering assist motor.
  4. Inspect the teeth (1) on the power steering assist motor gear and the large steering gear pulley.

    The teeth are directional and the NEW steering gear belt MUST be installed in the proper direction.

    Fig 2: Power Steering Assist Motor Gear And Large Steering Gear Pulley
    GM4229515Courtesy of GENERAL MOTORS COMPANY
  5. Hang the NEW steering gear belt on the large steering gear pulley.
  6. Install the nose of the power steering assist motor (1) into the steering gear housing and slide the steering gear belt onto the nose of the motor.
    Fig 3: Power Steering Assist Motor
    GM4258867Courtesy of GENERAL MOTORS COMPANY
    NOTE:
    • Do NOT pinch or roll the power steering assist motor seal while installing the power steering assist motor into the steering gear housing.
    • Before adding tension to the steering gear belt, ensure the belt is centered on the large steering gear pulley.
  7. After the power steering assist motor (1) is installed in the steering gear housing and steering gear belt, rotate the motor clockwise, while making sure the screw holes in the motor and slotted holes in steering gear housing are aligned properly.
  8. Install 5 space washers (1) and the OLD power steering assist motor pivot bolt (2).

    Tighten the OLD pivot bolt by hand.

    Fig 4: Space Washers And Old Power Steering Assist Motor Pivot Bolt
    GM4237432Courtesy of GENERAL MOTORS COMPANY
    NOTE:
    • The space washers will ensure the power steering assist motor is flush with the steering gear housing.
    • After hand tightening the OLD power steering assist motor pivot bolt, ensure the motor can still rotate.
  9. Use an open end wrench (1) to rotate the steering gear input shaft (2) 90 degrees in both directions and back to the center position to seat the steering gear belt.
    Fig 5: Steering Gear Input Shaft
    GM4258864Courtesy of GENERAL MOTORS COMPANY
  10. Use the following procedure to verify the steering gear rack is centered:
    1. Measure distance (a) from the top of the steering linkage outer tie rod to the steering gear boot inner clamp on either side of the steering gear rack.
    2. Measure distance (b) from the top of the steering linkage outer tie rod to the steering gear boot inner clamp on the opposite side of the steering gear rack.
    3. Verify both measurement (a) and measurement (b) are equal.
    4. If the measurements are not equal, turn the steering gear input shaft until the measurements are the same.
  11. Place the body of the GE-50576-A tester (1) on a flat surface or secure it to the steering gear housing and position the microphone of the tester 6 mm (0.25 in) from the steering gear belt. NEVER hold the tester by hand while taking measurements or the reading will be inaccurate.
    Fig 6: Belt Tension Sonic Gauge
    GM3553405Courtesy of GENERAL MOTORS COMPANY
  12. Use a finger to strum the steering gear belt (1) at the center location between the pulleys 3 times to get an average belt tension measurement.
    Fig 7: Steering Gear Belt
    GM4229516Courtesy of GENERAL MOTORS COMPANY
    1. If the average steering gear belt tension measurement is between 350-380 Hz then continue to the next step. If the average of the measurements is lower or higher than the specification, then rotate the power steering assist motor clockwise to tighten the belt or counterclockwise to loosen the belt, and take the average of another set of 3 measurements. Repeat this step until the average of the measurements is within the range specified and then tighten the power steering assist motor pivot bolt to 22 N.m (16 lb ft).
    2. Recheck the steering gear belt tension using the GE-50576-A tester. If the reading is not between 350-380 Hz then loosen the power steering assist motor pivot bolt and readjust the belt tension. If the measurement is still within the specified range then continue to the next step.
  13. Remove the OLD power steering assist motor pivot bolt and space washers.
  14. Install the NEW power steering assist motor pivot bolt (1) and tighten to 22 N.m (16 lb ft).
    Fig 8: Power Steering Assist Motor Pivot Bolt
    GM4258871Courtesy of GENERAL MOTORS COMPANY
  15. Use a clean shop rag to clean the steering gear housing cover mating surface on the steering gear housing so it is free of old grease and loose particles.
  16. Inspect the steering gear housing cover seal (1) and ensure the seal is seated correctly and that both dowel pins (2) are seated.

    If the seal is damaged, install a NEW seal.

    Fig 9: Steering Gear Housing Cover Seal
    GM4258873Courtesy of GENERAL MOTORS COMPANY
  17. Install the steering gear housing cover (1).
    Fig 10: Steering Gear Housing Cover
    GM4258870Courtesy of GENERAL MOTORS COMPANY
  18. Install the NEW steering gear housing cover bolts (1) and tighten by hand.
    Fig 11: Steering Gear Housing Cover Bolts
    GM4258869Courtesy of GENERAL MOTORS COMPANY
  19. Tighten the steering gear housing cover bolts in the following sequence:
    Fig 12: Steering Gear Housing Cover Bolts In Sequence
    GM4258874Courtesy of GENERAL MOTORS COMPANY
    1. M8 Bolts (1): 22 N.m (16 lb ft)
    2. M6 Bolts (2): 10 N.m (89 lb in)
  20. Connect the torque sensor wiring harness connector (1) to the power steering assist motor controller module.
    CAUTION: Ensure the torque sensor wiring harness is fully connected and seated to the electric power steering motor controller module. If the harness connector is not fully engaged, damage to the module will occur when the key is turned on and replacement of the module will be necessary.
    NOTE: The torque sensor wiring harness is NOT repairable. Do NOT attempt to repair the harness under any circumstances. If the harness is damaged then the steering gear MUST be replaced.
    Fig 13: Torque Sensor Wiring Harness Connector
    GM4258865Courtesy of GENERAL MOTORS COMPANY
  21. Steering Linkage Inner Tie Rod @ Belt Side» Install - Steering Linkage Inner Tie Rod Replacement 
  22. Remove the steering gear from the vise.
  23. Steering Gear» Install - Electric Belt Drive Rack and Pinion Steering Gear Replacement 
    CAUTION: During removal and installation, all EPS components including mechanical and/or electrical is extremely susceptible to damage. Dropping or prying on any EPS component may cause internal damage. If damage occurs or a part is dropped, the EPS component must be replaced.
    CAUTION: Care must be taken during removal and installation of the Electronic Power Steering (EPS) components to not hit or break the EPS motor/controller module or module harness connectors. If the EPS motor/ controller module or module connectors are damaged, the complete component must be replaced.
  24. Program the power steering control module. Refer to Control Module References