Strut Bearing

Replace the front strut bearing (upper strut mount) on a 2015-2020 Ford F-150 3.5L EcoBoost RWD, which eliminates clunking noises and restores smooth steering response.

Warnings

Tools required

Parts

• Front strut bearing/upper strut mount assembly × 1 — Ford BC3Z-18198-A or equivalent
• Upper strut mount hardware kit (if not included) × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and set parking brake firmly
2. Chock rear wheels securely
3. Loosen front wheel lug nuts 1/4 turn while vehicle is on ground
4. Lift front of vehicle and support on jack stands placed on frame rails behind lower control arms
5. Remove front wheel on side being serviced
6. Spray penetrating oil on strut-to-knuckle bolts and allow to soak for 10-15 minutes
7. Open hood and locate strut tower nuts (three nuts visible on top of strut tower)
8. Have assistant available to help support strut assembly during removal

Procedure

1. 1

   Disconnect sway bar link from strut
   Locate the sway bar link connection at the lower part of the strut assembly. Use a 6mm Allen key to hold the ball stud shaft while removing the upper nut with a wrench. Disconnect the sway bar link from the strut. If ball joint spins freely, use locking pliers on the rubber boot area (not the threaded stud).
   Torque spec

   Sway Bar Link70 Nm (52 lb-ft)
2. 2

   Mark strut-to-knuckle alignment
   Before removing strut-to-knuckle bolts, use a marker or paint pen to mark the position of the strut bracket relative to the steering knuckle. This preserves your camber alignment and minimizes the need for professional alignment afterward. Mark both the top and bottom positions clearly.
3. 3

   Remove strut-to-knuckle bolts
   Locate the two large bolts connecting the strut to the steering knuckle. Support the knuckle/hub assembly with your hand or a jack stand to prevent it from dropping. Remove both 18mm strut-to-knuckle bolts completely. The knuckle will now be free from the strut. You may need to pry gently between the strut bracket and knuckle to separate them.
   ⚠Support the knuckle assembly to prevent damage to brake line or ABS sensor wiring. Do not let knuckle hang by brake hose or wiring harness.
   Torque spec

   Strut-to-Knuckle Bolts140 Nm (104 lb-ft)
4. 4

   Remove strut tower mounting nuts
   Move to the engine bay. Locate the three 15mm nuts on top of the strut tower. Support the strut assembly from below with one hand or have an assistant hold it. Remove all three strut tower nuts. The center nut secures the strut shaft; the outer nuts secure the mount plate to the tower.
   ⚠The strut assembly is heavy (approximately 25-35 lbs). Ensure it is properly supported before removing the last nut to prevent it from falling.
   Torque spec

   Strut Tower Nuts50 Nm (37 lb-ft)
5. 5

   Remove strut assembly from vehicle
   Carefully lower the strut assembly down and out through the wheel well. Guide it past the brake rotor and control arm. Maneuver the strut assembly out of the vehicle and place it on a clean, stable work surface. Inspect the strut shaft for damage or leaking fluid.
6. 6

   Install spring compressor
   Install the coil spring compressor tools according to manufacturer instructions, positioning compressor hooks evenly around the spring coils (typically 180 degrees apart). Ensure hooks are fully engaged on the spring coils and not on the edge of coils. Begin compressing the spring gradually, alternating between compressor tools to maintain even compression. Compress until spring tension is relieved from the upper mount (you should be able to wiggle the mount slightly).
   ⚠️Spring compressors MUST be installed correctly per manufacturer instructions. Improper installation can cause spring to slip off compressor with lethal force. Compress evenly and gradually.
7. 7

   Remove strut shaft nut
   Hold the strut shaft with a 6mm or 8mm Allen key inserted in the top of the shaft (or use locking pliers on the shaft flats if equipped). Remove the 14mm shaft nut on top of the strut using a wrench or socket. Once nut is removed, carefully remove the upper mount plate, bearing assembly, spring seat, and any spacers or insulators, noting their exact order and orientation for reassembly.
   ⚠Take photos or make notes of the exact order and orientation of all components as you disassemble. Incorrect reassembly can cause noise, binding, or failure.
8. 8

   Remove old strut bearing
   Separate the upper strut mount assembly from the spring and strut. The bearing is typically integrated into the upper mount or sits between the mount and spring seat. Inspect the bearing for roughness, corrosion, or damage. Check the spring seat and isolator for cracks. Inspect the coil spring for damage or cracks. Clean the strut shaft threads with a wire brush.
9. 9

   Install new strut bearing and mount
   Install the new strut bearing/upper mount assembly onto the strut shaft, ensuring proper orientation (the offset position typically faces toward the engine bay). Install all spacers, insulators, and spring seats in the exact order they were removed. Verify the spring end is properly seated in the lower spring perch before proceeding. Align the upper spring seat with the spring end.
   ⚠The upper mount has a specific orientation relative to the strut lower mounting bracket. Verify alignment markings on mount match the strut bracket orientation before tightening shaft nut.
10. 10

    Install and torque strut shaft nut
    Thread the strut shaft nut onto the shaft by hand. Hold the strut shaft with an Allen key to prevent rotation, then torque the shaft nut to manufacturer specification (typically 65-80 Nm / 48-59 lb-ft, though not listed in provided specs - follow service manual or new part instructions). Ensure the bearing rotates smoothly without binding.
11. 11

    Release spring compressor
    Slowly and evenly release tension on the spring compressor tools, alternating between sides to maintain even decompression. Verify that the spring ends are properly seated in both the upper and lower spring seats as tension is released. Once spring is fully seated and carrying load, carefully remove the compressor tools.
    ⚠️Release spring compressor slowly and evenly. Verify spring ends remain properly seated throughout decompression. Never stand over or place body parts near the compressed spring during release.
12. 12

    Reinstall strut assembly into vehicle
    Guide the strut assembly up through the wheel well and into position. Align the three studs on the upper mount with the holes in the strut tower. Have an assistant support the strut from below or use a floor jack under the lower spring seat. Install the three strut tower nuts finger-tight, ensuring the mount is properly seated against the tower.
13. 13

    Connect strut to steering knuckle
    Raise the steering knuckle into position and align it with the strut bracket using the alignment marks made during disassembly. You may need to use a pry bar to spread the knuckle slightly or compress it to align the bolt holes. Insert both strut-to-knuckle bolts and install nuts finger-tight. Verify alignment marks match before proceeding.
14. 14

    Torque strut mounting hardware
    Torque the three strut tower nuts to 50 Nm (37 lb-ft) in a star pattern to ensure even seating. Then torque the two strut-to-knuckle bolts to 140 Nm (104 lb-ft). These bolts are critical for safety and must be torqued accurately.
    ⚠️Strut mounting bolts are safety-critical fasteners. Use a calibrated torque wrench and torque to exact specifications. Over-torquing or under-torquing can result in component failure.
    Torque spec

    Strut Tower Nuts50 Nm (37 lb-ft)

    Strut-to-Knuckle Bolts140 Nm (104 lb-ft)
15. 15

    Reconnect sway bar link
    Reconnect the sway bar link to the strut. Hold the ball stud shaft with a 6mm Allen key while torquing the nut to 55 Nm (41 lb-ft). Ensure the ball stud does not rotate during final torquing. Install wheel and torque lug nuts to 156 Nm (115 lb-ft) in a star pattern. Lower vehicle to ground.
    Torque spec

    Sway Bar Link70 Nm (52 lb-ft)

    Wheel Lug Nuts156 Nm (115 lb-ft)

Reassembly

1. After lowering vehicle, perform a final torque check on all wheel lug nuts with vehicle weight on the ground
2. If both front strut bearings were replaced, ensure both sides were torqued identically
3. Rock the vehicle side-to-side and listen for any unusual noises from the strut area
4. Test steering lock-to-lock while stationary to verify smooth operation without binding or noise

Verification

• Start engine and turn steering wheel lock-to-lock while stationary. Listen for smooth, quiet operation with no clicking or binding
• Test drive vehicle at low speed in a safe area. Listen for clunking noises over bumps and during turning
• Verify steering returns to center normally and feels responsive without play
• Check for any fluid leaks around strut body indicating strut damage during service
• Have vehicle alignment checked by a professional within 100 miles. Even with careful marking, alignment should be verified to prevent tire wear and handling issues
• Re-torque wheel lug nuts after 50-100 miles of driving

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