Leaf Spring U-Bolt Kit

Replace the rear leaf spring U-bolt kit on the 2023 Chevrolet Bolt EUV, securing the rear axle assembly to the leaf springs with new U-bolts and hardware.

Warnings

Tools required

Parts

• Leaf spring U-bolt kit (includes U-bolts, nuts, and mounting plate) × 1 — Use OEM specification
• Anti-seize compound × 1 — General purpose

Preparation

1. Ensure vehicle is parked on level, solid ground and in PARK with parking brake engaged
2. Power off the vehicle completely and remove the 12V battery negative terminal to prevent accidental power-on
3. Chock the front wheels to prevent rolling
4. Loosen rear wheel lug nuts while vehicle is on ground but do not remove
5. Raise the rear of the vehicle using a floor jack at the designated rear jacking points
6. Place jack stands under the rear frame rails at reinforced support points
7. Lower vehicle onto jack stands and verify stability before proceeding

Procedure

1. 1

   Remove rear wheel
   Finish removing the previously loosened lug nuts and remove the rear wheel on the side being serviced. Store lug nuts in a clean location.
2. 2

   Support rear axle assembly
   Position a floor jack under the rear axle housing near the U-bolt location to support the axle weight. Raise jack just enough to take slight pressure off the U-bolts but do not lift the vehicle. This prevents the axle from dropping when U-bolts are removed.
   ⚠The jack must remain in place throughout U-bolt removal and installation to control axle position.
3. 3

   Apply penetrating lubricant
   Spray penetrating lubricant on all U-bolt nuts and allow 10-15 minutes to soak. This helps prevent thread damage during removal, especially on corroded fasteners.
4. 4

   Remove U-bolt nuts
   Using a 19mm or 21mm socket (verify size on your specific U-bolts), remove all U-bolt nuts in a cross pattern to relieve tension evenly. Remove the mounting plate that sits between the nuts and the axle housing. Keep all old hardware together for reference.
5. 5

   Remove old U-bolts
   Extract the U-bolts from the leaf spring assembly. If U-bolts are seized or corroded, gently tap them out using a rubber mallet. Inspect the leaf spring mounting surface and mounting plate contact area on the axle housing for damage or excessive wear.
6. 6

   Clean mounting surfaces
   Use a wire brush to thoroughly clean the leaf spring top surface, axle housing bottom surface, and the area where the mounting plate sits. Remove all rust, corrosion, and debris to ensure proper seating of new components.
7. 7

   Position new U-bolts
   Verify the new U-bolt kit matches the old hardware. Position the new U-bolts around the leaf spring and through the mounting plate holes. Ensure the axle housing is properly seated in the leaf spring saddle with no gaps. The U-bolt threads should protrude evenly through the mounting plate.
   ⚠Verify proper axle-to-leaf spring alignment before installing nuts. Misalignment can cause handling issues and premature wear.
8. 8

   Install mounting plate and nuts
   Place the new mounting plate over the U-bolt threads. Apply a small amount of anti-seize compound to the U-bolt threads. Thread all U-bolt nuts onto the bolts by hand until finger-tight. Ensure the mounting plate is seated flat against the axle housing.
9. 9

   Torque U-bolt nuts to specification
   Using a torque wrench, tighten the U-bolt nuts in a cross pattern (diagonal sequence) to the manufacturer's specification. Since specific U-bolt torque is not listed in the database, consult the vehicle service manual for exact specification (typically 60-90 lb-ft for this class vehicle). Make multiple passes, increasing torque gradually in 20 lb-ft increments until final specification is reached.
   ⚠Uneven torque can cause U-bolt failure or leaf spring damage. Always use cross-pattern tightening and verify final torque on all nuts.
10. 10

    Verify installation and remove axle support
    Inspect the completed installation to ensure the mounting plate is flush, all nuts are properly torqued, and the axle housing is properly seated in the leaf spring. Carefully lower and remove the floor jack from under the axle assembly.
11. 11

    Reinstall wheel
    Mount the rear wheel back onto the hub. Thread all lug nuts by hand to prevent cross-threading. Using a torque wrench, tighten lug nuts in a star pattern to specification.
12. 12

    Lower vehicle and final torque check
    Raise the vehicle slightly off the jack stands using the floor jack. Remove jack stands and carefully lower the vehicle completely to the ground. With vehicle weight on the suspension, perform a final torque verification on all U-bolt nuts and wheel lug nuts.

Reassembly

1. Reconnect the 12V battery negative terminal
2. If both sides require U-bolt replacement, repeat the entire procedure for the opposite side
3. Dispose of old U-bolts and hardware properly

Verification

• Start the vehicle and verify no warning lights related to suspension or stability control appear
• Test drive the vehicle at low speed in a safe area and listen for any unusual noises from the rear suspension
• After 50-100 miles of driving, re-torque U-bolt nuts to specification as they may settle slightly during initial use
• Inspect for any signs of movement, looseness, or unusual tire wear after 500 miles

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