Replacement of the front coil springs on a 2015-2020 Ford F-150 3.5L EcoBoost, requiring strut disassembly and compressed spring removal.

Warnings

Tools required

Parts

• Front coil spring (left) × 1 — Use OEM specification or equivalent for F-150 EcoBoost RWD
• Front coil spring (right) × 1 — Use OEM specification or equivalent for F-150 EcoBoost RWD
• Strut upper mounting hardware kit × 1 — Includes bearing, isolator, and hardware
• Ball joint castle nut (if damaged) × 2 — M14 x 2.0 castle nut
• Cotter pin for ball joint × 2 — 3mm diameter

Preparation

1. Park vehicle on level, solid surface and engage parking brake
2. Loosen front wheel lug nuts while vehicle is on ground (do not remove)
3. Raise front of vehicle and support securely on jack stands placed under frame rails behind lower control arms
4. Remove both front wheels completely
5. Spray all suspension fasteners with penetrating oil and allow to soak (particularly ball joint nuts and strut bolts)
6. Take photos of strut orientation and spring positioning for reference during reassembly

Procedure

1. 1

   Disconnect sway bar link from strut
   Locate the sway bar end link connection at the strut. Insert a 6mm Allen key into the top of the link shaft to prevent rotation. Using a 15mm wrench, remove the nut securing the sway bar link to the strut. Allow the link to swing down and away from the strut assembly.
   Torque spec

   Sway Bar Link Nuts55 Nm (41 lb-ft)
2. 2

   Remove strut tower mounting nuts
   Open the hood and locate the three strut tower mounting nuts accessible from the engine bay. The front strut towers are visible near the inner fender wells. Using an 18mm wrench or socket, remove all three nuts from the top of the strut tower. Do not allow the strut shaft to spin; hold it with another wrench if necessary. Support the strut from below to prevent it from falling.
   ⚠Support the strut assembly from below before removing the final nut to prevent sudden drop.
   Torque spec

   Strut Tower Nuts50 Nm (37 lb-ft)
3. 3

   Separate ball joint from knuckle
   Locate the lower ball joint where the lower control arm connects to the steering knuckle. Remove the cotter pin from the castle nut. Using a 21mm socket, loosen but do not fully remove the ball joint castle nut (leave it threaded on a few turns). Use a ball joint separator tool or pickle fork to separate the ball joint taper from the knuckle. Once separated, remove the castle nut completely.
   ⚠Leave the castle nut threaded on a few turns while using the separator to prevent sudden release and component damage.
   Torque spec

   Ball Joint Nut101 Nm (75 lb-ft)
4. 4

   Remove strut-to-knuckle bolts
   Locate the two horizontal bolts connecting the bottom of the strut to the steering knuckle. These are typically 18mm bolts with nuts on the rear side. Support the strut assembly with one hand or a jack. Remove both bolts completely, supporting the strut to prevent it from falling. Carefully maneuver the strut assembly out from the knuckle and lower it from the vehicle.
   ⚠Strut assembly is heavy (approximately 40-50 lbs). Use proper lifting technique and get assistance if needed.
   Torque spec

   Strut Bolts133 Nm (98 lb-ft)
5. 5

   Install spring compressor on old spring
   Place the strut assembly on a clean, stable work surface. Install the spring compressor tools on opposite sides of the coil spring (180 degrees apart), ensuring the compressor hooks engage fully in the coil grooves. The compressor must be positioned so it compresses the spring evenly. Begin compressing the spring gradually, alternating between both compressor tools to maintain even compression. Continue until the spring is no longer under tension against the upper strut mount (spring should be loose enough that you can rotate it by hand).
   ⚠️Ensure spring compressor hooks are fully seated in coil grooves before applying compression. Compressor slippage can cause catastrophic spring release.
   ⚠️Compress spring slowly and evenly. Check compressor engagement frequently. Never lean over or place yourself in line with the spring during compression.
6. 6

   Remove strut shaft nut and upper mount
   With the spring fully compressed and loose, locate the strut shaft nut at the top center of the assembly. Hold the strut shaft with a wrench on the flats to prevent rotation. Using an 18mm socket, remove the upper strut shaft nut. Carefully lift off the upper mounting plate, bearing assembly, and upper spring isolator. Note the orientation and order of all components for reassembly.
   ⚠Keep all upper mount components in order. Take photos before disassembly to ensure correct reassembly sequence.
7. 7

   Remove old coil spring
   With the upper mount removed, carefully lift the compressed coil spring off the strut shaft. Keep the spring compressors installed and maintain compression. Set the old spring aside in a safe location where it cannot roll or fall. Inspect the strut for leaks, damage, or excessive wear. Replace the strut if any issues are found.
   ⚠️Keep spring compressors installed on the old spring until you are ready to transfer them to the new spring. Never release a compressed spring suddenly.
8. 8

   Install new coil spring
   Transfer the spring compressors to the new coil spring using the same positioning (180 degrees apart, fully seated in coil grooves). Compress the new spring evenly until it is short enough to fit on the strut assembly with clearance for the upper mount. Position the lower end of the spring into the spring seat on the strut, ensuring the spring end is properly seated in the locating tab or groove. Verify the spring is correctly oriented according to any directional markings.
   ⚠New springs may have directional markings or specific top/bottom orientation. Verify correct installation per spring manufacturer specifications.
9. 9

   Reinstall upper mount assembly
   Install a new or inspected upper spring isolator onto the top of the new spring. Place the bearing assembly and upper mounting plate onto the strut shaft in the correct orientation (reference your photos). Thread the strut shaft nut onto the shaft by hand. Hold the strut shaft to prevent rotation and torque the shaft nut to the manufacturer specification (typically 55-75 Nm, though not explicitly provided in specs). Ensure the upper mount components are properly seated.
   ℹ️While the specific strut shaft nut torque is not provided in the database, follow service manual specifications. The mounting bolt spec of 31 Nm may apply to upper mount hardware.
   Torque spec

   Mounting Bolts31 Nm (23 lb-ft)
10. 10

    Release spring compressor
    Carefully and evenly release the spring compressor tools, alternating between both sides to decompress the spring gradually. The spring will expand and seat against the upper mount. Once fully released, verify the spring ends are properly seated in both upper and lower spring seats. Remove the spring compressor tools completely and inspect the assembly.
    ⚠️Release spring compression slowly and evenly. Monitor that spring remains properly seated as tension is released.
11. 11

    Install strut assembly into vehicle
    Carefully lift the completed strut assembly into position, guiding the upper studs through the holes in the strut tower. Have an assistant support the assembly from the engine bay, or use a floor jack to hold it in position. Thread the three upper mounting nuts onto the studs by hand. Align the lower strut bracket with the steering knuckle and insert both strut-to-knuckle bolts from the front, installing nuts on the rear side. Do not fully tighten any fasteners yet.
12. 12

    Reconnect ball joint to knuckle
    Position the lower control arm ball joint stud into the steering knuckle hole. Thread the castle nut onto the ball joint stud by hand, then tighten to specification using a 21mm socket and torque wrench. Install a new cotter pin through the castle nut and ball joint stud, bending the ends to secure it properly.
    Torque spec

    Ball Joint Nut101 Nm (75 lb-ft)
13. 13

    Torque all suspension fasteners
    Working from top to bottom, torque all fasteners to specification. First, torque the three strut tower nuts to 50 Nm (37 lb-ft) using an 18mm socket. Next, torque both strut-to-knuckle bolts to 133 Nm (98 lb-ft). Finally, reconnect the sway bar link to the strut, holding the shaft with a 6mm Allen key and torquing the nut to 55 Nm (41 lb-ft) with a 15mm socket.
    Torque spec

    Strut Tower Nuts50 Nm (37 lb-ft)

    Strut Bolts133 Nm (98 lb-ft)

    Sway Bar Link Nuts55 Nm (41 lb-ft)
14. 14

    Repeat for opposite side
    Perform steps 1-13 for the opposite side front coil spring, following the same procedure exactly. Ensure both sides are completed with all fasteners properly torqued before lowering the vehicle.
15. 15

    Install wheels and lower vehicle
    Install both front wheels, threading lug nuts by hand to prevent cross-threading. Tighten lug nuts in a star pattern while vehicle is still on jack stands, but do not torque fully yet. Carefully lower the vehicle to the ground. With full vehicle weight on the wheels, torque lug nuts to 156 Nm (115 lb-ft) in a star pattern.
    Torque spec

    Wheel Lug Nuts156 Nm (115 lb-ft)

Reassembly

1. Verify all suspension fasteners are torqued to specification before test driving
2. Control arm bolts must be torqued to 165 Nm (122 lb-ft) with vehicle weight on wheels if they were disturbed during this procedure
3. Double-check that all cotter pins are properly installed and secured on ball joints
4. Inspect for any tools or parts left in the wheel well area before operation

Verification

• Test drive vehicle at low speed in a safe area, checking for unusual noises, vibrations, or handling issues
• Listen for any clunking or rattling from the front suspension over bumps
• Verify steering returns to center properly and vehicle tracks straight
• Re-torque all suspension fasteners after 50-100 miles of driving
• Have a professional four-wheel alignment performed as soon as possible after this repair
• Inspect for any fluid leaks around struts after test drive
• Confirm ride height is even side-to-side and appears normal for the vehicle

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