Power Window Motor - Rear

This procedure covers removal and replacement of the rear power window motor on a 1966 Chevrolet Corvette equipped with power windows.

Warnings

Tools required

Parts

• Power window motor (rear) × 1 — Use OEM specification
• Door panel retaining clips (if damaged) × 1 — Standard GM door panel clips
• Window regulator grease × 1 — White lithium grease
• Electrical connector (if corroded) × 1 — Standard GM weatherpack connector

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect negative battery cable to prevent electrical shorts during motor replacement
3. Roll rear window to approximately half-way position for easiest access to motor mounting bolts
4. Gather all tools and new parts before beginning disassembly
5. Cover rear deck area with shop towels to protect interior trim and collect hardware

Procedure

1. 1

   Remove rear interior trim panel
   Carefully pry up the rear interior quarter trim panel that covers the window mechanism. On the 1966 Corvette, this panel is secured with 4 Phillips screws along the bottom edge and snap clips along the top. Remove the screws first, then gently pull the panel away from the body using a trim tool or padded flat blade screwdriver. Work slowly to avoid breaking the clips or cracking the fiberglass mounting points.
2. 2

   Remove door/window sill trim
   Remove the rear window sill trim piece by locating and removing 2 Phillips screws at each end. This trim overlaps the quarter panel and must be removed to fully access the window regulator assembly. Set trim and hardware aside in a safe location.
3. 3

   Disconnect window motor electrical connector
   Locate the power window motor electrical connector near the motor mounting area. It is a power window motor connector; verify wire colors and function against the vehicle wiring diagram before disconnecting. Depress the locking tab and pull the connector straight off the motor terminals. Inspect the connector for corrosion; clean or replace if necessary. Mark wire orientation with masking tape if connector could be reversed.
4. 4

   Support the window glass
   Before removing motor mounting bolts, secure the window glass in its current position using masking tape applied from the exterior glass surface to the body. Alternatively, have an assistant hold the window in position. This prevents the window from dropping suddenly when the motor is disconnected from the regulator.
5. 5

   Disconnect motor from regulator mechanism
   Locate the drive gear connection between the motor and the window regulator. On the 1966 Corvette rear window, this is a sector gear arrangement. Remove the 3 bolts securing the motor bracket to the regulator plate using a 7/16" socket. The motor will separate from the regulator once these bolts are removed. Carefully guide the motor gear away from the regulator sector teeth.
6. 6

   Remove motor mounting bolts
   Remove the 2 bolts that secure the power window motor to its mounting bracket on the inner body structure. These are typically 3/8" hex head bolts. Support the motor with one hand while removing the final bolt to prevent it from falling. Carefully extract the motor through the access opening in the inner structure.
7. 7

   Inspect regulator mechanism
   With the motor removed, inspect the window regulator mechanism for worn or damaged components. Check the sector gear teeth for wear, missing teeth, or damage. Inspect the regulator tracks and rollers for binding or corrosion. Clean the regulator mechanism of old grease and debris, then apply fresh white lithium grease to all moving parts and gear teeth.
8. 8

   Prepare new motor for installation
   Remove the new power window motor from packaging and compare it to the original to verify correct replacement part. Check that the motor shaft rotates freely and the mounting holes align with the bracket. Apply a small amount of white lithium grease to the motor drive gear teeth before installation.
9. 9

   Install new motor to mounting bracket
   Position the new power window motor into the mounting bracket location and align the mounting holes. Insert and hand-tighten the 2 motor mounting bolts. Snug the bolts but do not fully tighten yet, as you may need to adjust motor position when engaging with the regulator.
10. 10

    Engage motor with regulator mechanism
    Carefully align the motor drive gear with the window regulator sector gear. Rotate the motor shaft slightly if needed to mesh the gear teeth properly. Once engaged, position the motor bracket against the regulator plate and install the 3 bracket-to-regulator bolts hand-tight. Verify smooth gear engagement by manually rotating the mechanism slightly.
11. 11

    Tighten all motor fasteners
    Tighten the 2 motor mounting bolts followed by the 3 motor bracket-to-regulator bolts. Work in a pattern to ensure even mounting pressure. Snug all fasteners firmly but do not overtighten into the fiberglass body structure.
12. 12

    Reconnect electrical connector
    Reconnect the electrical connector to the new power window motor terminals. Ensure the connector locks securely in place. Verify correct wire orientation if you marked the connector during removal.
13. 13

    Test motor operation
    Reconnect the negative battery cable. Remove the tape holding the window glass in position. Test the power window operation by cycling it up and down through its full range of motion several times. Listen for unusual noises, binding, or hesitation. Verify the window seats properly at full up position and travels smoothly throughout its range.
14. 14

    Reinstall interior trim
    Once window operation is verified, reinstall the rear window sill trim and secure with the 2 Phillips screws at each end. Reinstall the rear interior quarter trim panel by aligning the snap clips and pressing firmly into place, then install the 4 Phillips screws along the bottom edge. Verify all trim pieces are secure and properly aligned.

Reassembly

1. Ensure all electrical connections are secure and properly routed away from moving window mechanism components
2. Verify all trim fasteners are installed and trim panels seat flush against body
3. Test window operation one final time after all trim is reinstalled to confirm no interference

Verification

• Operate rear power window through complete up and down cycle 5 times, verifying smooth operation with no binding or unusual noise
• Confirm window fully seats at top of travel and auto-stops without over-running
• Check that window glass remains parallel to body throughout travel range
• Verify all interior trim panels are secure with no rattles or loose clips
• Confirm electrical connector is fully seated and locked

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