Remove and replace the rear transverse leaf spring on a 1966 Corvette, including U-bolt removal, spring detachment from differential carrier, and spring cushion inspection.

Warnings

Tools required

Parts

• Rear transverse leaf spring × 1 — Use OEM specification
• Spring cushion (differential carrier pad) × 1 — GM 3857594
• U-bolt nuts (if corroded) × 4 — 9/16"-18 grade 8
• Spring eye bushings (if worn) × 2 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake
2. Chock front wheels securely
3. Raise rear of vehicle using floor jack at differential carrier
4. Place jack stands under frame rails behind rear axle mounting points
5. Raise front of vehicle and place jack stands under front frame rails for stability
6. Remove both rear wheels for clearance and access
7. Spray all U-bolt nuts and spring mounting hardware with penetrating oil

Procedure

1. 1

   Remove shock absorber lower mounts
   Disconnect the lower shock absorber mounts on both sides. Remove the single 1/2" nut securing each shock to the strut rod bracket. Allow shocks to hang freely upward.
2. 2

   Remove U-bolt assemblies from both strut rods
   Remove the 4 nuts securing the two U-bolts that clamp the leaf spring to each strut rod bracket (8 nuts total, 4 per side). Use a 9/16" socket. The U-bolts capture the spring against the strut rod lower surface. Once nuts are removed, lift U-bolts away from strut rods.
3. 3

   Remove differential carrier center mounting bolt
   Locate the single through-bolt that secures the leaf spring center section to the top of the differential carrier, passing through the spring eye and carrier mount pad. This is typically a 9/16" bolt head. Support the spring with your hand or a floor jack positioned under the spring center. Remove the bolt and washer completely.
4. 4

   Lower and remove leaf spring
   Carefully lower the floor jack (if used) or manually guide the spring downward. The spring will pivot at the front and rear frame bracket attachment points. Work the spring free from the strut rod brackets on both sides. Once clear of the struts, pull the spring forward or rearward to disengage one end from its frame bracket mounting bolt, then remove the spring from under the vehicle.
5. 5

   Inspect spring eye bushings and frame brackets
   Examine the rubber bushings pressed into each spring eye (front and rear attachment points). Check for cracking, tearing, or excessive wear. Inspect the frame bracket mounting bolts for thread damage. If bushings are worn, press out old bushings and press in new ones using a hydraulic press or bushing driver set.
6. 6

   Inspect and replace differential carrier cushion
   Remove the rubber spring cushion pad from the top of the differential carrier where the spring center eye mounts. This pad is typically glued or friction-fit. Inspect for compression damage, cracking, or hardening. Install new cushion if worn, ensuring proper orientation with any locating tabs aligned.
7. 7

   Clean all mounting surfaces
   Use a wire brush to clean the strut rod U-bolt mounting surfaces, frame bracket bolt areas, and differential carrier mounting pad. Remove rust, old undercoating, and debris to ensure proper seating of the new spring.
8. 8

   Position new leaf spring onto frame brackets
   Maneuver the new leaf spring into position under the vehicle. Align one spring eye with its frame bracket and insert the mounting bolt finger-tight. Flex or pivot the spring to align the opposite end with its frame bracket and insert that mounting bolt finger-tight. Do not fully torque these bolts yet.
9. 9

   Raise spring center to differential carrier
   Using a floor jack positioned under the spring center, carefully raise the spring until the center eye aligns with the differential carrier mounting pad. Ensure the rubber cushion is properly seated. Insert the center through-bolt and washer. Thread nut onto bolt finger-tight.
10. 10

    Install U-bolts onto strut rod brackets
    Position the leaf spring against the bottom of each strut rod bracket. Place U-bolts over the strut rod with legs straddling the spring. Install flat washers and nuts onto all 4 U-bolt legs at each side (8 nuts total). Thread nuts finger-tight, ensuring spring is centered in the U-bolt clamps.
11. 11

    Torque all spring mounting fasteners
    Torque the differential carrier center bolt to 50 ft-lb. Torque all 8 U-bolt nuts in a cross pattern (alternate sides) to 45 ft-lb. Finally, torque the front and rear spring eye frame bracket bolts to 60 ft-lb. This sequence ensures even spring load distribution.
12. 12

    Reconnect shock absorber lower mounts
    Align each shock absorber lower eye with the strut rod bracket mounting point. Install the 1/2" bolt, washer, and nut. Torque shock mounting nuts to 35 ft-lb.

Reassembly

1. Reinstall both rear wheels and torque lug nuts to 80 ft-lb in a star pattern
2. Remove all four jack stands
3. Lower vehicle completely to the ground
4. Bounce rear of vehicle several times to settle suspension
5. Re-check all fastener torque values after settling

Verification

• Visually inspect all U-bolt nuts and spring mounting bolts for proper seating and torque
• Check that spring center is properly seated on differential carrier cushion with no gaps
• Bounce rear of vehicle and listen for any rattles or clunking indicating loose hardware
• Take vehicle for short test drive and verify stable handling with no unusual noises
• Re-torque all spring fasteners after 50-100 miles of driving

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