Leaf Spring U-Bolt Kit

Replace the leaf spring U-bolt kit on the rear suspension to secure the axle to the leaf springs and restore proper clamping force.

Warnings

Tools required

Parts

• Leaf spring U-bolt kit (includes 4 U-bolts, nuts, and spring plates per side) × 1 — Use OEM specification or equivalent aftermarket
• Anti-seize compound × 1 — Standard copper or nickel-based

Preparation

1. Park vehicle on level, solid ground and engage parking brake
2. Place wheel chocks in front of both front wheels
3. Loosen rear wheel lug nuts while vehicle is on ground (do not remove)
4. Spray penetrating oil on U-bolt nuts and allow to soak if visible corrosion is present
5. Gather all tools and new parts, inspect U-bolt kit for completeness

Procedure

1. 1

   Raise and support vehicle
   Using a floor jack, raise the rear of the vehicle at the frame rails. Place jack stands under the frame rails on both sides, ensuring they are secure and rated for the vehicle weight. Lower the vehicle onto the jack stands. The rear axle should hang freely but remain close to normal ride height.
2. 2

   Remove rear wheels
   Remove the loosened lug nuts completely and remove both rear wheels. Set wheels aside in a safe location away from the work area.
   Torque spec

   Wheel Lug Nuts169 Nm (125 lb-ft)
3. 3

   Support the rear axle
   Position a floor jack under the rear axle housing near the differential. Raise the jack just enough to make light contact and support the axle weight. This prevents the axle from dropping when U-bolts are removed and maintains leaf spring position.
4. 4

   Remove U-bolt nuts on one side
   Starting with the driver or passenger side (complete one side at a time), remove all four U-bolt nuts from the U-bolts. Use a socket and breaker bar if necessary. Keep track of any washers. The U-bolts pass through the spring plate and secure the axle to the leaf spring.
5. 5

   Remove old U-bolts and spring plate
   Once all nuts are removed, pull the U-bolts down and out from the spring plate. Remove the lower spring plate from beneath the leaf spring. Inspect the spring plate for damage or excessive wear. If the axle seats are worn or damaged, they should also be replaced.
6. 6

   Clean mounting surfaces
   Use a wire brush to clean the top of the leaf spring pad, the bottom of the axle housing contact area, and both sides of the spring plate mounting surface. Remove all rust, dirt, and old thread sealant. Clean the threaded holes in the spring plate if reusing.
7. 7

   Position new spring plate and U-bolts
   Position the new lower spring plate under the leaf spring. Ensure the axle housing is properly seated in the leaf spring saddle with the centering pin aligned. Insert the new U-bolts from the top, through the spring plate, around the axle housing, and through the lower spring plate. Apply a small amount of anti-seize to the U-bolt threads.
8. 8

   Install U-bolt nuts finger tight
   Thread all four U-bolt nuts onto the U-bolts by hand. Ensure the spring plate is positioned correctly and square with the axle. Tighten nuts in a crisscross pattern using a ratchet until they are snug but not torqued. This ensures even seating of components.
9. 9

   Torque U-bolt nuts to specification
   Using a torque wrench, tighten the U-bolt nuts in a crisscross pattern (diagonal pairs) to the manufacturer specification. For 2014-2018 Silverado 1500 rear leaf spring U-bolts, torque to 110-120 ft-lbs in multiple passes. Start at 50 ft-lbs, then 80 ft-lbs, then final specification. Verify all four nuts are torqued evenly.
10. 10

    Repeat for opposite side
    Repeat steps 4 through 9 for the opposite side of the vehicle. Ensure the floor jack remains positioned to support the axle during the process. Verify both sides have new U-bolts properly torqued.
11. 11

    Reinstall rear wheels
    Mount both rear wheels back onto the hubs. Thread lug nuts by hand to prevent cross-threading. Tighten lug nuts in a star pattern with a ratchet, but do not torque yet.
    Torque spec

    Wheel Lug Nuts169 Nm (125 lb-ft)
12. 12

    Lower vehicle and final torque
    Carefully raise the vehicle slightly with the floor jack to remove jack stands. Lower the vehicle completely to the ground. Using a torque wrench, torque the wheel lug nuts to 169 Nm (125 ft-lbs) in a star pattern to ensure even pressure distribution.
    Torque spec

    Wheel Lug Nuts169 Nm (125 lb-ft)

Reassembly

1. Double-check that all U-bolt nuts are torqued to specification on both sides
2. Verify wheel lug nuts are properly torqued after vehicle is on the ground
3. Remove all tools and equipment from under the vehicle

Verification

• Visually inspect both sides to confirm all U-bolt nuts are installed and tight
• Rock the vehicle side to side to check for any loose components or unusual noises
• Test drive the vehicle at low speed and verify no clunking or unusual handling
• After 50-100 miles of driving, re-torque U-bolt nuts as they may settle slightly during initial use
• Check that the axle remains properly centered under the vehicle with no side-to-side shift

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