Replace the rear leaf spring U-bolt kit, including U-bolts, mounting plates, and hardware that secure the rear axle housing to the leaf springs on a 1966 Corvette.

Warnings

Tools required

Parts

• Rear leaf spring U-bolt kit (includes 4 U-bolts, 4 mounting plates, 8 nuts) × 1 — Use OEM specification or aftermarket equivalent for 1966 Corvette

Preparation

1. Park vehicle on level, solid surface and engage parking brake
2. Place wheel chocks in front of front wheels
3. Loosen rear wheel lug nuts while vehicle is on ground
4. Raise rear of vehicle using floor jack at rear crossmember or differential housing
5. Place jack stands under frame rails behind rear axle, ensuring vehicle is stable
6. Raise front of vehicle and place jack stands under front frame rails to level vehicle and prevent shifting
7. Remove both rear wheels completely
8. Apply penetrating oil to all U-bolt nuts and allow to soak while preparing tools

Procedure

1. 1

   Support the rear axle assembly
   Position a hydraulic transmission jack or secondary jack stands under the rear differential housing to support the axle assembly weight. Raise slightly until the jack just contacts the housing but does not lift the vehicle. The axle must remain supported throughout U-bolt removal to prevent it from dropping or shifting position on the leaf springs.
2. 2

   Remove the first U-bolt assembly (driver side front)
   Locate the front U-bolt on the driver side rear axle. Using a 9/16" socket and breaker bar, loosen and remove both nuts from the U-bolt threads. The U-bolt passes through the mounting plate on top of the leaf spring and around the axle housing. Once nuts are removed, tap the U-bolt upward with a hammer to break it free from corrosion, then remove the U-bolt and upper mounting plate. Inspect the spring pad between the axle and leaf spring for damage.
3. 3

   Remove the second U-bolt assembly (driver side rear)
   Repeat the removal process for the rear U-bolt on the driver side. Remove both nuts using a 9/16" socket, then extract the U-bolt and mounting plate. With both driver side U-bolts removed, the axle housing will be free on this side but should remain supported by your jack.
4. 4

   Inspect and clean the driver side mounting surfaces
   With U-bolts removed, use a wire brush to clean the top surface of the leaf spring and the bottom surface of the axle housing where the spring pad sits. Remove all rust, old rubber debris, and corrosion. Inspect the leaf spring for cracks, broken leaves, or excessive wear. Check that the axle spring pad (rubber cushion between axle and spring) is present and in serviceable condition.
5. 5

   Install new driver side U-bolts
   Position the new mounting plate on top of the leaf spring, aligning the holes with the spring. Ensure the axle housing is properly centered on the spring and the spring pad is correctly positioned. Insert the first new U-bolt around the axle housing and through the mounting plate holes. Thread both nuts onto the U-bolt finger-tight. Repeat for the second U-bolt. Do not torque at this stage.
6. 6

   Remove passenger side U-bolt assemblies
   Move to the passenger side and repeat the removal process. Remove both nuts from the front U-bolt using a 9/16" socket, extract the U-bolt and mounting plate. Repeat for the rear U-bolt. Clean all mounting surfaces with a wire brush and inspect components as done on the driver side.
7. 7

   Install new passenger side U-bolts
   Install the new mounting plates and U-bolts on the passenger side following the same procedure as the driver side. Position mounting plates, insert U-bolts around the axle housing, and thread all nuts finger-tight. Ensure the axle housing is centered on both leaf springs before proceeding to torque specifications.
8. 8

   Torque U-bolt nuts to specification
   Beginning with the driver side front U-bolt, torque both nuts in a cross pattern to 45 ft-lbs. Then torque to final specification of 80 ft-lbs in a cross pattern (alternating between the two nuts). Move to the driver side rear U-bolt and repeat the torque sequence to 80 ft-lbs. Repeat the entire torque procedure for both passenger side U-bolts. This cross-tightening pattern ensures even clamping force and proper axle alignment.

Reassembly

1. Reinstall both rear wheels and thread lug nuts finger-tight
2. Lower vehicle from jack stands by raising with floor jack, removing stands, then carefully lowering to ground
3. Torque wheel lug nuts to 80 ft-lbs in a star pattern
4. Remove wheel chocks

Verification

• Bounce the rear of the vehicle several times to settle the suspension, then re-check U-bolt torque after the vehicle has settled
• Visually inspect all U-bolt installations to confirm mounting plates are seated flush against leaf springs
• Test drive vehicle at low speed and verify no abnormal noises, clunking, or rear axle movement
• Re-torque all U-bolt nuts after 50-100 miles of driving to account for settling

More procedures for this vehicle