GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 1999 🢒 Century (China) (CNG) 🢒 Body and Accessories 🢒 Seats 🢒 Seat Adjuster Phase Adjustment

Removal Procedure
  1. Remove the front seat from the vehicle. Refer to Front Seat Replacement - Bucket .

    2. Object Number: 310458 Size: SH
  2. Remove the front seat with the adjusters attached.
  3. Place the front seat upside down on a clean protected surface.
  4. Disconnect the electrical connectors, if equipped.
  5. Remove the finish panels. Refer to Front Seat Trim Panel Replacement .
  6. Remove the seat cushion cover. Refer to Front Seat Cushion Cover Replacement .
  7. Remove the seat cushion pad.
  8. Remove the adjuster to seat cushion frame bolts.
  9. Remove the adjuster from the seat cushion frame.
  10. Remove the drive cables. Refer to Seat Horizontal and Vertical Drive Cable Replacement .
  11. Separate the left and the right adjusters by removing the crossbrace bolts and the crossbrace.

Installation Procedure

    Object Number: 310458 Size: SH

    Important: When you install the power seat adjusters, verify that the adjusters are parallel and in phase with each other. The adjusters are out of phase if one adjuster reaches its maximum horizontal or vertical travel before the other adjuster. If the adjusters are out of phase, phase the adjusters.

  1. Attach a crossbrace to the left and right adjusters.

    2. Ensure that the tab bending downward at the center of the crossbrace faces the rear of the adjusters.

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  2. Secure the crossbrace with 2 bolts.

    Tighten
    Tighten the crossbrace bolts to 6 N·m (53 lb in).

  3. Install the drive cables. Refer to Seat Horizontal and Vertical Drive Cable Replacement .
  4. Install the seat to adjuster assembly.
  5. Install the adjuster to seat cushion frame bolts.

    6. Tighten
    Tighten the adjuster to seat cushion frame bolts to 24 N·m (18 lb ft).

  6. Install the seat cushion pad.
  7. Install the seat cushion cover. Refer to Front Seat Cushion Cover Replacement .
  8. Install the finish panels. Refer to Front Seat Trim Panel Replacement .
  9. Connect the electrical connectors, if equipped.
  10. Install the front seat. Refer to Front Seat Replacement - Bucket .