Window Motor and Regulator - Rear

This procedure covers the removal and replacement of the rear window motor and regulator assembly on a 1966 Chevrolet Corvette coupe, including interior trim removal and electrical disconnection.

Warnings

Tools required

Parts

• Rear window regulator assembly × 1 — Use OEM specification or quality aftermarket
• Rear window motor × 1 — Use OEM specification
• Interior panel retaining clips × 1 — As needed for damaged clips
• Electrical connector (if corroded) × 1 — Use OEM specification
• Window track grease × 1 — White lithium grease or silicone-based

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect negative battery cable to prevent electrical shorts
3. Ensure rear window is in the full up position if possible before beginning work
4. Protect interior trim and glass with masking tape or towels to prevent scratches
5. Have a container ready for small fasteners and clips

Procedure

1. 1

   Remove interior quarter trim panel
   From inside the vehicle, locate and remove the interior quarter trim panel covering the rear window area. Remove the 4 Phillips head screws securing the upper trim panel. Carefully pry the panel away from the body using trim removal tools, releasing the retaining clips along the edges. Work slowly to avoid breaking clips or cracking the fiberglass body.
2. 2

   Remove lower access panel
   Locate the lower access panel below the rear window area. Remove the 3 screws securing this panel and set aside. This provides access to the lower regulator mounting points and motor.
3. 3

   Support the window glass
   Before disconnecting the regulator, secure the window glass in the up position using masking tape from glass to body, or have an assistant hold it, or use suction cup glass holders. This prevents the glass from falling when the regulator is disconnected.
4. 4

   Disconnect window motor electrical connector
   Locate the window motor electrical connector inside the quarter panel cavity. Carefully separate the original-style electrical connector (typically a bullet or spade connector) by pulling it apart gently. Inspect the connector for corrosion or damage. If connector is corroded, plan to replace it during reassembly.
5. 5

   Disconnect regulator from window glass
   Locate the 2 bolts securing the regulator arm to the window channel bracket at the bottom of the glass. Use the appropriate SAE socket (typically 7/16") to remove these bolts. Gently lower the regulator arm away from the glass channel. The glass should now be free from the regulator but supported by your temporary support method.
6. 6

   Remove window motor mounting fasteners
   Locate the 3 bolts securing the window motor to the mounting bracket inside the door cavity. Use the appropriate SAE socket (typically 5/16" or 3/8") to remove these bolts. Support the motor as you remove the last bolt to prevent it from falling.
7. 7

   Remove regulator mounting fasteners
   Locate the regulator mounting points. Remove the bolts securing the regulator track and assembly to the inner quarter panel structure using the appropriate SAE socket. Verify exact bolt count against the factory assembly manual. Note the position of any spacers or shims behind the regulator mounting points for proper reinstallation.
8. 8

   Remove regulator and motor assembly
   Carefully maneuver the regulator assembly out through the access opening in the quarter panel. The regulator may need to be tilted and rotated to clear the opening. Remove the motor if it is still attached to the regulator. Take photos or make notes of the regulator orientation for installation reference.
9. 9

   Inspect and clean mounting area
   Inspect the window channel tracks for debris, old grease, or damage. Clean the tracks thoroughly with a cloth and mild solvent. Inspect mounting holes in the fiberglass for cracks or damage. Check the window glass for chips or cracks at the mounting points.
10. 10

    Install new window motor to regulator
    If the motor is separate from the regulator, attach the new or replacement motor to the regulator assembly. Secure with the 3 mounting bolts and tighten snugly. Ensure the motor pinion gear is properly engaged with the regulator sector gear.
11. 11

    Install regulator assembly
    Maneuver the new regulator assembly into the quarter panel cavity through the access opening. Align the regulator mounting holes with the body mounting points. Install any spacers or shims that were noted during removal. Install the 5 regulator mounting bolts and tighten securely, but do not overtighten into fiberglass.
12. 12

    Connect regulator to window glass
    Raise the regulator arm to align with the window channel bracket at the bottom of the glass. Install the 2 bolts securing the regulator arm to the glass channel and tighten with the appropriate SAE socket (typically 7/16"). Ensure the connection is secure but do not overtighten.
13. 13

    Reconnect electrical connector and test
    Connect the window motor electrical connector. Temporarily reconnect the negative battery cable. Test the window operation through its full range of motion. Window should move smoothly up and down without binding. If window binds or moves slowly, check regulator alignment and track condition. Disconnect battery again before final reassembly.
14. 14

    Lubricate window tracks
    Apply a thin coat of white lithium grease or silicone-based lubricant to the window tracks and regulator sliding points. Do not over-lubricate as excess grease can attract dirt.
15. 15

    Reinstall trim panels
    Reinstall the lower access panel and secure with its 3 screws. Reinstall the quarter trim panel by aligning the retaining clips and pressing firmly into place. Install the 4 upper panel screws. Ensure all clips are fully seated and panel fits flush.

Reassembly

1. Reconnect the negative battery cable
2. Test window operation multiple times to ensure smooth movement
3. Check that all trim panels are secure and properly aligned
4. Verify no rattles or unusual noises during window operation

Verification

• Operate window through full up and down cycle at least 3 times to confirm smooth operation
• Check for any binding or slow spots in window travel
• Verify window seals properly at full up position
• Confirm no electrical issues or blown fuses
• Inspect interior trim panels for proper fit and secure mounting
• Listen for any unusual motor or regulator noises during operation

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