Procedure for removing and replacing the front radius arm (also known as the lower control arm strut rod) on a 1966 Chevrolet Corvette with independent front suspension.

Warnings

Tools required

Parts

• Radius arm (lower control arm strut rod) × 1 — Use OEM specification or equivalent aftermarket
• Radius arm bushings (front and rear) × 1 — Use OEM specification
• Radius arm mounting hardware kit × 1 — Includes bolts, washers, and nuts

Preparation

1. Park vehicle on level, solid surface and engage parking brake.
2. Place wheel chocks behind rear wheels.
3. Loosen front wheel lug nuts while vehicle is on ground.
4. Raise front of vehicle using floor jack at designated front crossmember jacking point.
5. Support vehicle securely on jack stands placed under frame rails, not suspension components.
6. Remove front wheel on the side being serviced.
7. Spray all radius arm mounting fasteners with penetrating oil and allow to soak for at least 30 minutes.

Procedure

1. 1

   Support the lower control arm
   Position floor jack under the lower control arm ball joint area to support the suspension weight. Raise jack just enough to slightly compress the suspension, taking load off the radius arm. This prevents the suspension from dropping suddenly when the radius arm is disconnected.
2. 2

   Locate radius arm mounting points
   Identify the radius arm running from the lower control arm forward to the front crossmember. The rear mount attaches to a bracket on the lower control arm. The front mount attaches to a bracket on the front crossmember with a through-bolt and bushings.
3. 3

   Remove rear radius arm mounting bolt
   Using a combination wrench to hold the nut, remove the rear mounting bolt that connects the radius arm to the lower control arm bracket. Verify exact bolt size against the factory 1966 Corvette service manual before ordering hardware. Support the radius arm as you remove the bolt to prevent it from dropping.
4. 4

   Remove front radius arm mounting bolt
   Locate the front mounting bolt that passes through the radius arm bushing and crossmember bracket. Verify exact bolt size against the factory 1966 Corvette service manual before ordering hardware. Use a breaker bar if necessary to break the bolt free, then remove the bolt, washers, and nut. Note the orientation and sequence of any washers or spacers for reassembly.
5. 5

   Remove radius arm from vehicle
   With both mounting bolts removed, carefully extract the radius arm from the vehicle. You may need to manipulate the suspension slightly or use a pry bar to work the arm free from the mounting brackets. Inspect the old arm for damage or bending.
6. 6

   Inspect and clean mounting brackets
   Examine both the front crossmember bracket and lower control arm bracket for cracks, damage, or excessive wear. Use a wire brush to clean all mounting surfaces, bolt holes, and threads. Use a thread chaser or tap to clean bolt hole threads if necessary.
7. 7

   Prepare new radius arm
   If bushings are not pre-installed on the new radius arm, install new bushings at both front and rear mounting points according to manufacturer instructions. Ensure bushings are properly seated and oriented. If applying anti-seize compound to mounting bolt threads, reduce the target torque value accordingly (typically by 15-25%) since the published torque specs assume clean, dry threads.
8. 8

   Install new radius arm at front mount
   Position the new radius arm with the front end inserted into the crossmember bracket. Insert the front mounting bolt through the bracket, bushing, and opposite bracket side. Install washers and nut finger-tight only at this stage. Ensure proper orientation matches the original installation.
9. 9

   Connect rear mount to lower control arm
   Align the rear end of the radius arm with the lower control arm mounting bracket. You may need to use the floor jack to adjust suspension height slightly for proper alignment. Insert the rear mounting bolt through the bracket and arm, then install washer and nut finger-tight.
10. 10

    Bring suspension to ride height
    Using the floor jack under the lower control arm, raise the suspension to simulate normal ride height (wheels on ground position). This ensures the radius arm bushings are torqued in their neutral, untwisted position, which is critical for bushing longevity and proper suspension geometry.
11. 11

    Torque radius arm fasteners
    With suspension at ride height, torque the mounting fasteners to the factory specifications listed in the 1966 Corvette service manual; do not rely on estimated values for safety-critical suspension fasteners. If factory specifications are available, use those values instead. Hold the nut with a wrench while torquing the bolt head to prevent spinning.
12. 12

    Lower suspension and remove jack
    Carefully lower the floor jack to release pressure from under the lower control arm. Remove the jack completely from under the vehicle. Verify all fasteners are secure and properly torqued.

Reassembly

1. Reinstall wheel and torque lug nuts to 80 ft-lbs in a star pattern.
2. Lower vehicle completely to ground.
3. Re-torque wheel lug nuts to final specification of 80 ft-lbs after vehicle is on ground.
4. Bounce front end of vehicle several times to settle suspension.

Verification

• Visually inspect both radius arm mounting points to confirm fasteners are properly installed and torqued.
• Check that radius arm does not contact any surrounding components through full suspension travel.
• Test drive vehicle at low speed in a safe area and verify no unusual noises, vibrations, or handling issues.
• Schedule a professional front-end alignment as soon as possible, as suspension geometry has been altered.

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