GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2000 🢒 Yukon Denali 🢒 Body and Accessories 🢒 Doors 🢒 Outside Rearview Mirror Glass Replacement

Removal Procedure

    Object Number: 277784 Size: SH
  1. Remove the mirror from the door. Refer to Outside Rearview Mirror Replacement .
  2. Remove the damaged mirror back and glass sub-assembly from the mirror housing by completing the following steps:
    3. 2.1. Insert your fingers as far as possible behind the mirror back toward the center of the back.
    2.2. With force sufficient in order to disengage the trunnion from the motor pack, pull straight out of the housing the mirror back.
  3. Inspect the motor pack top for any damage to the trunnion area.
  4. Remove the remaining jack screws that may remain in the motor pack helical gear openings.
  5. Clean the glass from the inside of the mirror frame.

Installation Procedure

    Object Number: 277784 Size: SH
  1. Remove the replacement mirror back and the glass sub-assembly.
  2. Inspect the components for damage. Ensure that the mirror back and glass sub-assembly has a trunnion bar and 2 jack screws.
  3. Align the mirror back jack screws with the helical gear openings.
  4. Gently press toward the motor pack the mirror back.

    5. Apply slight pressure on the jack screws at the helical gear openings.

  5. In the replacement of a left mirror, complete the following steps:
    6. 5.1. Actuate the mirror in a downward travel.

    This action pulls the up/down jack screw into the motor pack.

    5.2. Discontinue actuation when the travel draws in 50 percent of the length of the up/down jack screw.
    5.3. Actuate the mirror in a leftward travel.

    This action pulls the left/right jack screw into the motor pack.

    5.4. Discontinue actuation when the travel draws in 50 percent of the length of the left/right jack screw.
  6. In the replacement of a right mirror, complete the following steps:
    7. 6.1. Actuate the mirror in a downward travel.

    This action pulls the up/down jack screw into the motor pack.

    6.2. Discontinue actuation when the travel draws in 50 percent of the length of the up/down jack screw.
    6.3. Actuate the mirror in a rightward travel.

    This action pulls the left/right jack screw into the motor pack.

    6.4. Discontinue actuation when the travel draws in 50 percent of the length of the left/right jack screw.

    Important: Proper alignment of the trunnion prevents damage to the motor pack trunnion receptor area.

  7. Look over the top of the mirror back into the mirror housing.

    8. Manipulate the mirror back in order to align the mirror back trunnion into the motor pack receptor area.

    Important: Do not strike the glass. Uniformly apply increasing pressure.

  8. Place the palm of your hand on the center of the glass.

    9. Firmly press the glass toward the motor pack in order to achieve proper insertion.

    The insertion is complete when the mirror back trunnion nests in the motor pack trunnion area.

  9. In order to test the installation, press the glass with your hand in order to move the glass in each direction.

    10. Observe for the following conditions that indicate a successful installation:

    • The mirror back remains firmly attached to the motor pack.
    • Electrical actuation of the mirror is possible.
  10. Install the mirror to the door. Refer to Outside Rearview Mirror Replacement .