This procedure covers the removal and replacement of rear leaf springs on a 2015-2020 Ford F-150 with 3.5L EcoBoost engine, including U-bolt removal, spring pivot bolt removal, and installation of new springs.

Warnings

Tools required

Parts

• Rear leaf spring assembly × 1 — Use OEM specification or aftermarket equivalent
• Leaf spring U-bolts × 2 — Replace if corroded or damaged
• U-bolt nuts × 4 — Replace with new hardware
• Front spring eye bushing × 1 — Inspect and replace if worn
• Rear spring shackle bushings × 2 — Inspect and replace if worn
• Spring shackle plates × 2 — Replace if bent or damaged

Preparation

1. Park vehicle on level, solid surface and engage parking brake
2. Chock the front wheels securely
3. Loosen rear wheel lug nuts while vehicle is on ground
4. Raise rear of vehicle using floor jack at rear differential or frame rails
5. Support vehicle on jack stands placed at manufacturer-specified frame points
6. Remove rear wheel on the side being serviced
7. Spray all leaf spring mounting bolts, U-bolt nuts, and shackle bolts with penetrating oil
8. Inspect brake lines and ABS sensor wires for routing and potential interference

Procedure

1. 1

   Support the rear axle
   Place a floor jack under the rear axle housing near the spring being serviced. Raise just enough to take slight pressure off the leaf spring, but do not lift the vehicle off the jack stands. This supports the axle weight during spring removal.
2. 2

   Remove U-bolt nuts
   Using an 18mm socket, remove the four U-bolt nuts securing the spring to the axle. Remove the U-bolts completely. Note the orientation and any spacer plates between the spring and axle housing for reassembly.
   ⚠U-bolts may be severely corroded. Use penetrating oil and heat if necessary, but avoid excessive heat near brake components.
3. 3

   Disconnect shock absorber lower mount
   Locate the lower shock absorber mounting bolt at the axle bracket. Remove the bolt using a 21mm socket to allow clearance for spring removal. Support the shock to prevent it from hanging on the brake line.
4. 4

   Remove rear shackle bolts
   At the rear of the leaf spring, locate the shackle assembly connecting the spring to the frame bracket. Remove the upper and lower shackle bolts using an 18mm socket and wrench. The spring will now be free at the rear.
   ⚠Support the spring with your hand as you remove the second shackle bolt to prevent it from dropping.
5. 5

   Remove front spring eye bolt
   At the front of the leaf spring, remove the through-bolt securing the spring eye to the front hanger bracket using an 18mm socket and wrench. You may need to use a breaker bar as this bolt typically has high torque. Lower the jack slightly to relieve tension if the bolt is difficult to remove.
6. 6

   Remove leaf spring assembly
   With all mounting points disconnected, carefully lower the jack supporting the axle slightly and maneuver the leaf spring assembly out from under the vehicle. Note the position of any spacer blocks or anti-squeak pads for reinstallation.
7. 7

   Inspect mounting points and clean surfaces
   Inspect the front hanger bracket, rear shackle bracket, and axle spring perch for damage, cracks, or excessive wear. Wire brush all mounting surfaces on the axle and frame to remove rust and debris. Check that the axle spring perch is flat and not distorted.
8. 8

   Install new leaf spring front mount
   Position the new leaf spring with the front eye aligned with the front hanger bracket. Insert the front eye bolt but do not fully tighten yet. Thread the nut on several turns to hold the spring in position. Ensure any factory-installed bushings are properly seated.
9. 9

   Attach rear shackle assembly
   Align the rear of the leaf spring with the shackle plates and frame bracket. Install the shackle bolts through the spring eye and frame bracket. Thread nuts on several turns but do not fully tighten. The spring should now be suspended at both ends.
10. 10

    Position spring on axle
    Use the floor jack to carefully raise the axle until the spring seats properly on the axle spring perch. Verify the center locating pin on the spring (if equipped) engages with the hole in the axle perch. Install any spacer blocks between the spring and axle in their original positions.
11. 11

    Install U-bolts
    Position new U-bolts over the axle housing and through the mounting plate. Thread all four nuts onto the U-bolts hand-tight. Tighten the nuts in a crisscross pattern in multiple stages to ensure even clamping pressure. Final torque specification is typically 85-95 lb-ft, but verify with manufacturer specifications as this torque is not listed in the provided database.
    ℹ️U-bolt torque is critical for proper spring-to-axle clamping. Tighten in stages: 40 lb-ft, then 65 lb-ft, then final torque in a crisscross pattern.
12. 12

    Reconnect shock absorber
    Align the lower shock mount with the axle bracket and install the mounting bolt. Torque the shock lower mounting bolt to manufacturer specification (typically 85 lb-ft, but not provided in database).
13. 13

    Torque spring mounting bolts
    With the vehicle weight still on jack stands, torque the front spring eye bolt and rear shackle bolts to manufacturer specification (typically 85-110 lb-ft for spring eye bolts, but not provided in database). These must be torqued with the suspension at ride height for proper bushing life.
    ℹ️Spring mounting bolts must be torqued with suspension at normal ride height to prevent bushing wind-up and premature failure.
14. 14

    Reinstall wheel
    Install the wheel and thread lug nuts hand-tight. Lower the vehicle until the tire just contacts the ground but the suspension is not fully loaded.
    Torque spec

    Wheel Lug Nuts156 Nm (115 lb-ft)
15. 15

    Final torque at ride height
    Remove jack stands and lower the vehicle completely to the ground. With full vehicle weight on the suspension, re-torque the front spring eye bolt and rear shackle bolts to specification. Torque wheel lug nuts to 156 Nm (115 lb-ft) in a star pattern.
    Torque spec

    Wheel Lug Nuts156 Nm (115 lb-ft)

Reassembly

1. Repeat all steps for the opposite side if replacing both leaf springs
2. Verify all fasteners are torqued to specification with vehicle at ride height
3. Check that brake lines and ABS sensor wires have adequate clearance and are properly routed
4. Ensure shock absorber is properly connected at both upper and lower mounts

Verification

• Test drive the vehicle at low speed and verify no unusual noises from the rear suspension
• Check for proper ride height and compare side-to-side to ensure even installation
• Re-torque U-bolt nuts after 50-100 miles of driving as they may settle
• Inspect all mounting bolts for tightness after initial test drive
• Verify rear axle alignment is within specification; alignment may be needed after spring replacement

More procedures for this vehicle