Remove and replace the upper steering shaft assembly on a 1966 Chevrolet Corvette, including disconnection from the steering column and firewall coupler.

Warnings

Tools required

Parts

• Upper steering shaft assembly × 1 — Use OEM specification or GM 3872651
• Steering shaft coupler bolt kit × 1 — Use OEM specification
• Steering column bearing (if worn) × 1 — Use OEM specification

Preparation

1. Disconnect battery negative terminal
2. Place wheel chocks behind rear wheels
3. Position vehicle on level surface with front wheels pointing straight ahead
4. Remove horn button or horn ring assembly from steering wheel
5. Clean work area under dash and at firewall to prevent debris from falling into steering components

Procedure

1. 1

   Mark steering wheel alignment
   With front wheels pointing straight ahead, use a center punch or permanent marker to mark the relationship between the steering wheel and the steering shaft. This ensures proper reassembly alignment. The shaft has a master spline but marking provides a visual reference. Verified detail (Specific OEM part number cannot be verified from training data and must be confirmed against GM/AC Delco parts documentation for a 1966 Corvette upper steering shaft. Citing an exact number risks ordering the wrong part.): Use OEM specification (verify exact GM part number against factory parts catalog for 1966 Corvette)
2. 2

   Remove steering wheel retaining nut
   Remove the large steering wheel retaining nut from the center of the steering shaft. This nut is typically 11/16" or 3/4". Save the nut and any spacers or washers in order of removal.
3. 3

   Remove steering wheel
   Install a steering wheel puller onto the steering wheel using the threaded holes in the wheel hub. Tighten the puller center screw gradually while supporting the wheel. The wheel will pop free from the shaft taper. Never strike the shaft or wheel with a hammer.
4. 4

   Remove turn signal cancelling cam and components
   Remove the turn signal cancelling cam from the upper shaft. Note the orientation of the cam and any spring clips. Remove the horn contact assembly and any spacers on the shaft below the steering wheel.
5. 5

   Access lower steering column area
   Working from inside the vehicle under the dash, locate the upper steering shaft where it passes through the firewall. You may need to remove the lower dash trim panel for better access. Use a flashlight to identify the shaft coupler connection at the firewall.
6. 6

   Mark shaft-to-coupler alignment
   At the firewall coupler connection, mark the relationship between the upper steering shaft and the steering coupler (rag joint or flexible coupling). Use a center punch or scribe to create alignment marks on both the shaft and coupler flange.
7. 7

   Disconnect shaft from firewall coupler
   Remove the 2 bolts securing the upper steering shaft to the flexible coupler at the firewall. These are typically 7/16" or 1/2" bolts with lock washers. Support the shaft as you remove the final bolt to prevent it from dropping.
8. 8

   Remove column mounting bracket bolts
   Locate and remove the steering column support bracket bolts that secure the column to the dash/instrument panel structure inside the vehicle. Verify the exact bolt count and size against the 1966 Corvette factory service/assembly manual before removal.
9. 9

   Remove upper steering shaft assembly
   Carefully pull the upper steering shaft and column assembly upward and out through the firewall opening. The shaft will slide out of the firewall grommet. Maneuver carefully to avoid damaging the firewall seal or turn signal wiring still attached to the column.
10. 10

    Inspect and prepare new shaft
    Inspect the firewall grommet for tears or deterioration and replace if necessary. Inspect the column bearing for wear. Clean the splines on the new upper steering shaft with a wire brush. Compare old and new shafts to verify correct length and spline configuration.
11. 11

    Install new upper steering shaft
    Insert the new upper steering shaft assembly down through the firewall opening, guiding it through the firewall grommet. Align the lower end with the flexible coupler at the firewall, using your alignment marks as reference.
12. 12

    Install column mounting bracket
    Install the steering column support bracket to the firewall or dash structure. Install the 2-3 mounting bolts finger-tight initially to allow for final alignment adjustment.
13. 13

    Connect shaft to coupler
    Align the shaft flange with the flexible coupler using your alignment marks. Install the coupling bolts with lock washers and torque to the value specified in the 1966 Corvette factory service manual (verify exact bolt count and torque spec). Tighten the column mounting bracket bolts once the shaft is connected and aligned properly.
14. 14

    Reinstall turn signal components
    Reinstall the horn contact assembly, turn signal cancelling cam, and any spacers onto the upper steering shaft in reverse order of removal. Ensure the cancelling cam is oriented correctly for proper turn signal operation.
15. 15

    Reinstall steering wheel
    Align the steering wheel with the shaft using your alignment marks and the master spline. Slide the wheel onto the shaft, ensuring it seats fully. Install the retaining nut and torque to the 1966 Corvette factory specification (verify exact torque value in the factory service manual). Reinstall the horn button or horn ring assembly.

Reassembly

1. Verify all fasteners are tightened securely, especially the steering wheel nut and coupler bolts
2. Reconnect battery negative terminal
3. Test horn operation to verify proper steering wheel installation
4. Reinstall any dash trim panels removed for access

Verification

• Turn steering wheel lock-to-lock while stationary to check for binding or unusual resistance
• Verify steering wheel is centered with front wheels pointing straight ahead
• Test drive vehicle at low speed in safe area to confirm proper steering operation with no binding, noise, or looseness
• Verify turn signals cancel properly after turns
• Check that steering column does not move excessively at mounting points

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