This procedure addresses the removal and installation of an electric power steering motor on a 1966 Chevrolet Corvette. Note: 1966 Corvettes were equipped with manual steering as standard; this procedure assumes an aftermarket electric power steering (EPS) system has been installed.

Warnings

Tools required

Parts

• Electric power steering motor assembly × 1 — Match existing aftermarket EPS system brand and model
• EPS wiring harness (if damaged) × 1 — Match existing aftermarket EPS system
• Electrical connectors and terminals × 1 — Use OEM specification
• Thread locking compound (medium strength) × 1 — Loctite 243 or equivalent

Preparation

1. Park vehicle on level ground and engage parking brake securely
2. Place wheel chocks behind rear wheels
3. Photograph or diagram all electrical connections and wiring routing for the EPS system before disconnection
4. Disconnect negative battery cable and isolate it away from the battery terminal
5. Allow engine to cool completely if recently operated
6. Determine the exact type and mounting location of the aftermarket EPS system (common types: column-mounted assist, rack-mounted assist, or inline steering shaft assist)
7. Have replacement EPS motor and any necessary mounting hardware ready

Procedure

1. 1

   Access the EPS motor location
   Depending on the aftermarket EPS system type, access the motor location. For column-mounted systems, remove the lower dash panel and steering column covers. For rack-mounted or inline shaft systems, raise and support the front of the vehicle on jack stands, then remove the front wheels if necessary to access the steering components from below. Remove any splash shields or underbody panels blocking access to the EPS motor.
2. 2

   Disconnect EPS electrical connections
   Locate the main power connector(s) to the EPS motor. Most aftermarket systems have a main power connector and a control module connector. Label each connector with tape and marker for reassembly reference. Carefully disconnect all electrical connectors from the EPS motor, noting connector orientation and any locking tabs. Use electrical contact cleaner on connectors if corrosion is present.
3. 3

   Test and document electrical supply
   Before removing the motor, use a multimeter to verify the power supply circuit. With the key in the ON position (battery reconnected temporarily for testing, then disconnected again), check for proper voltage at the EPS motor power connector. Document the voltage readings and verify they match the EPS system specifications (typically 12-14 volts DC). This confirms whether the issue is motor failure or electrical supply failure.
4. 4

   Remove EPS motor mounting hardware
   Remove the mounting bolts securing the EPS motor to its bracket or steering column. Mounting bolt count varies by aftermarket EPS system and configuration; verify the actual count for your installed unit before removal. Apply penetrating oil if fasteners are corroded. Support the motor weight during bolt removal to prevent it from falling. Keep all mounting hardware organized for reinstallation.
5. 5

   Disconnect mechanical steering coupling
   If the EPS motor is inline with the steering shaft, locate the coupling or universal joint connecting the motor output to the steering shaft. Remove the pinch bolt(s) securing the coupling. Mark the relative position of the coupling halves with a paint pen or scribe to maintain proper steering alignment during reassembly. Carefully separate the coupling to free the motor.
6. 6

   Remove EPS motor assembly
   Carefully withdraw the EPS motor from its mounting location. Note any shims, spacers, or alignment pins that may be present. Inspect the mounting bracket and surrounding area for damage, cracks, or wear that may have contributed to motor failure. Clean the mounting surfaces thoroughly.
7. 7

   Compare old and new EPS motors
   Place the old and new EPS motors side-by-side and verify they are identical in physical dimensions, mounting hole pattern, shaft diameter and length, and electrical connector configuration. Confirm the new motor's electrical specifications (voltage, amperage rating) match the original. Transfer any brackets or adapters from the old motor to the new one if they are not included with the replacement.
8. 8

   Install new EPS motor
   Position the new EPS motor into the mounting location, ensuring any alignment pins or locating features are properly seated. If applicable, align the motor shaft with the steering shaft coupling, referencing the alignment marks made during disassembly. Hand-thread all mounting bolts to verify proper fit before final tightening.
9. 9

   Secure motor mounting bolts
   Tighten the EPS motor mounting bolts in a cross-pattern to ensure even seating. Apply medium-strength thread locking compound to bolt threads. Since specific torque specifications vary by aftermarket manufacturer, always tighten bolts to the EPS manufacturer's published torque specification. Do not guess a value: if specifications are unavailable, contact the manufacturer, as steering-component fastener torque depends on bolt size and grade (e.g. M6 ~7 ft-lbs, M8 ~17 ft-lbs, M10 ~35 ft-lbs). Verify the motor is solidly mounted with no movement.
10. 10

    Reconnect mechanical steering coupling
    Reconnect the steering shaft coupling to the EPS motor output shaft, aligning the marks made during disassembly to maintain proper steering alignment. Install the pinch bolt(s) and tighten securely. Verify the coupling has no excessive play and that the steering shaft rotates smoothly through its full range of motion.
11. 11

    Reconnect electrical connections
    Reconnect all electrical connectors to the new EPS motor, referencing the labels and photographs taken during disassembly. Ensure connectors are fully seated and locking tabs engage properly. Route wiring along the original path, securing with zip ties or wire loom as needed to prevent chafing or interference with moving parts.
12. 12

    Verify electrical connections and ground
    Check that all electrical connections are clean and tight. Verify the EPS motor ground connection is secure and making good contact with clean metal. Poor grounding is a common cause of EPS malfunction. Use a multimeter to test continuity between the motor ground terminal and chassis ground.
13. 13

    Reconnect battery and initialize system
    Reconnect the negative battery cable. Turn the ignition key to the ON position without starting the engine. Many aftermarket EPS systems require an initialization procedure: turn the steering wheel fully lock-to-lock 2-3 times slowly to allow the control module to learn center position and range of motion. Consult the specific EPS system documentation for initialization requirements.
14. 14

    Test EPS motor operation
    With the engine running, test the EPS motor operation by turning the steering wheel through its full range. The steering effort should be noticeably reduced compared to manual steering, and should feel smooth and consistent. Listen for any unusual noises from the motor such as grinding, clicking, or buzzing that might indicate a problem.

Reassembly

1. Reinstall all access panels, dash components, underbody shields, and wheels that were removed for access
2. Verify all fasteners are tight and no tools or parts have been left in the work area
3. Double-check that all electrical connections are secure and wiring is properly routed and secured

Verification

• Start the engine and verify the EPS system activates (most systems have an indicator light or audible confirmation)
• With the vehicle stationary and engine running, turn the steering wheel lock-to-lock and verify smooth power assist throughout the range
• Check for any error codes or warning lights related to the steering system
• Perform a low-speed test drive in a safe area to verify steering assist is working properly during actual driving conditions
• Verify steering returns to center smoothly when released
• Re-check all mounting bolts and electrical connections after test drive
• Confirm no abnormal noises from the EPS motor during operation

More procedures for this vehicle