This procedure covers the replacement of both rear coil springs on a 2021-2024 Ford F-150 with 3.5L EcoBoost engine, including suspension disassembly and proper spring compressor use.

Warnings

Tools required

Parts

• Rear coil spring (left) × 1 — Use OEM specification or equivalent aftermarket
• Rear coil spring (right) × 1 — Use OEM specification or equivalent aftermarket
• Spring isolator pads (upper and lower) × 4 — Inspect and replace if damaged

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 1/4 turn while vehicle is on ground
4. Raise rear of vehicle using floor jack on rear differential or frame rails
5. Support vehicle securely on jack stands positioned at manufacturer-specified frame contact points behind rear axle
6. Remove both rear wheels completely
7. Spray penetrating oil on all shock and suspension fasteners and allow 15-30 minutes to soak
8. Inspect springs and surrounding components for damage or excessive corrosion

Procedure

1. 1

   Support the rear axle
   Position a floor jack under the rear axle housing near the center or under the side you are working on first. Raise the jack just enough to contact the axle and take slight load off the suspension, but do not lift the axle. This provides control during disassembly. You will work on one side at a time.
   ⚠The jack must remain in position throughout spring removal to control axle movement. Do not fully raise the axle as this will load the spring and prevent removal.
2. 2

   Disconnect rear shock absorber lower mount (first side)
   Locate the lower shock absorber mounting bolt at the rear axle bracket. Using the appropriate socket (typically 18-21mm), remove the lower shock mounting bolt completely. Push the shock absorber upward out of the way and secure it with a bungee cord or wire to prevent it from hanging on the brake line.
   ⚠Do not allow shock absorber to hang freely as it may damage brake lines or wiring.
3. 3

   Lower axle to release spring tension
   Carefully and slowly lower the floor jack supporting the rear axle. Lower it until the coil spring is fully extended and loose between the upper spring seat (frame) and lower spring seat (axle). The spring should have no load on it and may have slight movement. Stop lowering when spring is free but before the axle drops too far and stresses brake lines or other components.
   ⚠️Monitor brake hoses, ABS wiring, and parking brake cables as you lower the axle. Do not overextend these components. Stop lowering if any component becomes tight.
   ⚠Lower the axle slowly and steadily. Sudden drops can damage components or cause the spring to fall unexpectedly.
4. 4

   Remove spring and isolators
   Carefully remove the coil spring from between the frame and axle mounts. You may need to rotate it or tilt it to clear the mounting points. Remove the upper and lower spring isolator pads (rubber cushions) from both ends of the spring. Inspect isolators for cracking, compression damage, or deterioration and replace if necessary.
5. 5

   Compare and prepare new spring
   Compare the new coil spring to the old spring to verify correct part number, height, and coil count. Check that spring end configurations match (pigtail orientation). Install new or reused upper and lower spring isolator pads onto the new coil spring, ensuring they are properly seated in the spring end coils.
   ⚠Installing the wrong spring rate or height will affect ride quality and vehicle handling. Verify part number matches your specific F-150 model and payload configuration.
6. 6

   Install new spring
   Position the new coil spring between the upper frame mount and lower axle mount. Ensure the spring pigtail ends are oriented correctly in their respective seats - the tapered end of the spring coil should sit in the matching recess in both upper and lower spring seats. Verify isolator pads remain properly positioned.
7. 7

   Raise axle and compress spring
   Slowly raise the floor jack to lift the rear axle back to normal ride height position. As you raise the axle, the spring will compress between the upper and lower seats. Continue raising until the lower shock mount on the axle aligns with the shock absorber lower mounting hole. Verify spring remains properly seated in both upper and lower mounts.
   ⚠️Ensure the spring is properly seated in both mounts before raising the axle. A misaligned spring can slip out violently when compressed.
8. 8

   Reinstall shock absorber lower mount
   Align the shock absorber lower eye with the mounting bracket on the axle. Insert the lower shock mounting bolt and thread on the nut. Tighten the bolt to specification. Note: If your torque spec list includes shock-specific torque values, use those; otherwise tighten to 98 ft-lb as a typical value for this application.
   Torque spec

   Strut Bolts133 Nm (98 lb-ft)
9. 9

   Repeat for opposite side
   Reposition the floor jack to support the opposite side of the rear axle. Repeat steps 2 through 8 for the second rear coil spring. Ensure both springs are the same part number and properly oriented in their mounts.
10. 10

    Reinstall wheels
    Mount both rear wheels onto the hubs and hand-thread all lug nuts. Tighten lug nuts in a star pattern to draw the wheel evenly onto the hub, but do not torque to final specification yet.
11. 11

    Lower vehicle and torque wheels
    Remove jack stands and carefully lower the vehicle completely to the ground. With vehicle weight on the wheels, torque all wheel lug nuts to specification in a star pattern.
    Torque spec

    Wheel Lug Nuts156 Nm (115 lb-ft)

Reassembly

1. All suspension components must be tightened with vehicle weight on suspension at normal ride height
2. Verify spring isolator pads are properly positioned and not displaced during installation
3. Ensure no brake lines, ABS wiring, or parking brake cables are pinched or stressed
4. Check that shock absorbers move freely through their travel range

Verification

• Bounce each rear corner of the vehicle several times and verify springs are seated properly with no unusual noises
• Verify rear ride height is even side-to-side and matches front-to-rear rake specifications
• Test drive vehicle at low speed in a safe area and verify normal handling with no clunking or rattling from rear suspension
• After 50-100 miles, re-check wheel lug nut torque
• Have wheel alignment checked by a professional, as ride height changes can affect alignment angles

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