This procedure covers the removal and replacement of the rear leaf spring assembly on a 2021-2024 Ford F-150 RWD with the 3.5L EcoBoost engine.

Warnings

Tools required

Parts

• Rear leaf spring assembly × 1 — Use OEM specification
• U-bolt kit (4 bolts, 2 plates) × 1 — OEM replacement recommended
• Leaf spring bushings (front and rear) × 1 — Use OEM specification
• Shackle bushings × 1 — Use OEM specification

Preparation

1. Park vehicle on level ground and engage parking brake
2. Chock the front wheels securely
3. Loosen rear wheel lug nuts while vehicle is on the ground
4. Raise rear of vehicle and support frame rails with jack stands rated for vehicle weight
5. Remove rear wheel on the side being serviced
6. Spray all leaf spring mounting bolts, U-bolts, and shackle hardware with penetrating oil and allow to soak for 10-15 minutes

Procedure

1. 1

   Support the rear axle
   Position a floor jack under the rear axle housing near the leaf spring being replaced. Raise jack until it just contacts the axle and supports its weight, but does not lift the vehicle. The axle must remain supported throughout the entire procedure to prevent it from dropping suddenly.
2. 2

   Remove U-bolts
   Locate the U-bolts that secure the leaf spring to the axle housing. Remove the four nuts from the U-bolts. Remove the U-bolt retaining plate and then extract the U-bolts from the spring and axle assembly. Set hardware aside if reusing.
   ⚠Support the spring as the last U-bolt is removed to prevent it from shifting suddenly.
3. 3

   Disconnect rear shackle
   Locate the rear shackle where the back of the leaf spring connects to the frame. Remove the bolt that secures the shackle to the leaf spring. You may need to support the spring with your hand or a pry bar to align the bolt for removal. Do not remove the shackle-to-frame bolt yet.
4. 4

   Remove front mounting bolt
   Locate the front leaf spring eye bolt that connects to the front spring hanger on the frame. Remove the nut and bolt. The spring may need to be pried slightly to remove the bolt if bushings are worn or corroded. Once removed, the spring should be free to lower.
5. 5

   Remove leaf spring
   Carefully lower the leaf spring assembly away from the axle. You may need to gently pry it free if corrosion has caused binding. Remove the spring from the vehicle. If the spring does not come free easily, verify all mounting hardware has been removed.
6. 6

   Inspect and clean mounting points
   With the spring removed, inspect all mounting points on the frame and axle for rust, damage, or wear. Use a wire brush to clean the U-bolt seat area on the axle housing and the spring mounting brackets on the frame. Inspect the rear shackle assembly for wear or damage and replace if necessary.
7. 7

   Install new bushings
   If replacing bushings, press or drive the new front eye bushing into the spring eye and install the new rear eye bushing. Install new shackle bushings if equipped. Ensure bushings are fully seated and oriented correctly per manufacturer specifications.
   ℹ️Some bushings may require a press or specialized installation tool. Do not use excessive force that could damage the spring eye.
8. 8

   Position new leaf spring
   Lift the new leaf spring into position. Insert the front eye bolt through the spring eye and front hanger bracket. Install the nut but do not fully tighten yet. The spring should pivot freely on this bolt.
9. 9

   Connect rear shackle
   Align the rear spring eye with the shackle and insert the bolt through the shackle and spring eye. Install the nut hand-tight. Verify the spring is positioned correctly before proceeding.
10. 10

    Install U-bolts
    Raise the floor jack to lift the axle into contact with the leaf spring center section. Ensure the spring is properly centered on the axle housing and the axle locating pin (if equipped) engages the spring center hole. Position the U-bolt retaining plate and install the new U-bolts. Thread nuts onto all four U-bolt ends and tighten evenly in a cross pattern to seat the components, but do not torque to final specification yet.
11. 11

    Torque U-bolts and mounting hardware
    With the vehicle weight now on the suspension (axle raised by jack), torque the U-bolt nuts evenly in a cross pattern to manufacturer specification. Then torque the front eye bolt nut and rear shackle bolt nut to specification. Verify all hardware is properly tightened.
    ℹ️U-bolt torque specifications are not provided in the database. Consult factory service manual for this critical specification, typically 120-150 Nm (88-111 lb-ft) for F-150, but verify for your specific model year.
12. 12

    Reinstall wheel
    Install the rear wheel onto the hub. Thread lug nuts on by hand and tighten in a star pattern. Lower the vehicle until the tire just contacts the ground but the full weight is not on the wheel yet.
    Torque spec

    Wheel Lug Nuts156 Nm (115 lb-ft)
13. 13

    Final torque wheel lug nuts
    Lower the vehicle completely to the ground and remove jack stands. Torque the wheel lug nuts to specification in a star pattern. Remove the floor jack from under the axle.
    Torque spec

    Wheel Lug Nuts156 Nm (115 lb-ft)

Reassembly

1. Double-check that all fasteners have been installed and torqued to specification
2. Verify the leaf spring is properly seated on the axle and centered
3. Remove all tools and equipment from under the vehicle

Verification

• Perform a visual inspection of all mounting points to ensure hardware is properly installed
• Test drive the vehicle at low speed 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
• Check vehicle ride height is even side-to-side

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