This procedure covers the removal and replacement of the rear lower control arm on a 2015-2020 Ford F-150 with 3.5L EcoBoost engine, including disconnection of the ball joint and control arm mounting points.

Warnings

Tools required

Parts

• Rear lower control arm × 1 — Use OEM specification or quality aftermarket equivalent
• Ball joint castle nut (if not reusable) × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake
2. Chock the front wheels to prevent rolling
3. Loosen rear wheel lug nuts while vehicle is on ground (do not remove)
4. Raise rear of vehicle with floor jack at designated rear axle jacking point
5. Support vehicle securely on jack stands under the frame rails
6. Remove rear wheel completely
7. Spray all fasteners with penetrating oil and allow 10-15 minutes to soak

Procedure

1. 1

   Support the rear knuckle assembly
   Position a floor jack under the rear knuckle/hub assembly to support it and control the suspension position. Raise jack just enough to take slight load off the control arm, simulating normal ride height position. This prevents the suspension from dropping and damaging brake lines or ABS wiring when the control arm is disconnected.
2. 2

   Remove ball joint castle nut
   Locate the lower control arm ball joint where it connects to the rear knuckle. Remove the cotter pin if equipped. Using an 18mm socket, remove the castle nut from the ball joint stud. Keep the nut if it is in good condition; replace if worn or damaged.
   Torque spec

   Ball Joint Nut101 Nm (75 lb-ft)
3. 3

   Separate ball joint from knuckle
   Use a ball joint separator tool or pickle fork to separate the ball joint stud from the knuckle. Position the tool between the control arm and knuckle, then strike with a hammer or use the screw-type separator to apply pressure. The ball joint should pop free. If using a pickle fork, be aware this may damage the ball joint boot if reusing the control arm.
   ⚠Keep hands and face clear when separating the ball joint as it may release suddenly under tension.
4. 4

   Remove front control arm mounting bolt
   Locate the front mounting bolt that secures the control arm to the front bushing bracket on the frame or subframe. Using a 21mm socket and breaker bar, remove the bolt completely. This is typically the forward-most attachment point. Note the orientation and any washers or spacers for reinstallation.
   Torque spec

   Control Arm Bolts165 Nm (122 lb-ft)
5. 5

   Remove rear control arm mounting bolt
   Locate the rear mounting bolt that secures the control arm to the rear bushing bracket. Using a 21mm socket and breaker bar, remove this bolt completely. The control arm should now be free to remove. You may need to manipulate the jack under the knuckle slightly to create clearance.
   Torque spec

   Control Arm Bolts165 Nm (122 lb-ft)
6. 6

   Remove lower control arm
   Carefully pull the control arm away from the vehicle. The ball joint stud should slide out of the knuckle if not already separated. Maneuver the control arm out of the wheel well, being careful not to damage brake lines, ABS sensors, or other components. Inspect the bushings and ball joint on the old arm to verify the cause of replacement.
7. 7

   Prepare new control arm and mounting points
   Clean the mounting bolt holes in the frame brackets with a wire brush to remove rust and debris. Inspect the mounting bolts for damage or excessive corrosion; replace if necessary. Compare the new control arm to the old one to ensure correct part. Check that the ball joint boot is intact and the bushings are properly seated in the new arm.
8. 8

   Install new control arm
   Position the new control arm into place, aligning the front and rear bushing holes with the frame mounting brackets. Insert the ball joint stud into the hole in the rear knuckle. You may need to use the floor jack to raise or lower the knuckle slightly to align the ball joint. A rubber mallet can help seat the ball joint stud fully into the knuckle taper.
9. 9

   Install control arm mounting bolts finger-tight
   Insert the front and rear control arm mounting bolts through the bushings and into the frame brackets. Thread the bolts in by hand and tighten with a socket until snug, but DO NOT torque to specification yet. The vehicle must be at normal ride height (weight on wheels) before final torque is applied to prevent bushing bind.
10. 10

    Install and torque ball joint nut
    Thread the castle nut onto the ball joint stud by hand, then tighten to specification using an 18mm socket and torque wrench. Torque to 101 Nm (75 lb-ft). If using a castle nut, align the slots with the cotter pin hole in the stud and install a new cotter pin. If slots don't align at proper torque, tighten further (never loosen) to the next slot alignment.
    Torque spec

    Ball Joint Nut101 Nm (75 lb-ft)
11. 11

    Reinstall wheel
    Remove the floor jack from under the knuckle. Reinstall the rear wheel onto the hub, threading all lug nuts by hand first. Tighten lug nuts in a star pattern with a hand wrench until snug, but do not torque yet.
12. 12

    Lower vehicle to ground
    Carefully raise the vehicle slightly with the floor jack to remove the jack stands. Slowly lower the vehicle until the wheels are fully supporting the vehicle weight on the ground. This loads the suspension to the normal ride height position, which is required before final torquing of the control arm bolts.
13. 13

    Torque wheel lug nuts
    With the vehicle on the ground, use a torque wrench and 21mm socket to torque the wheel lug nuts to 156 Nm (115 lb-ft) in a star pattern. This ensures even seating of the wheel against the hub.
    Torque spec

    Wheel Lug Nuts156 Nm (115 lb-ft)
14. 14

    Torque control arm mounting bolts
    Access the control arm mounting bolts from under the vehicle (you may need to raise slightly and support with jack stands for access, but keep wheels on ground supporting weight). Using a 21mm socket and torque wrench, torque both the front and rear control arm bolts to 165 Nm (122 lb-ft). This must be done with vehicle weight on the suspension to prevent bushing preload and premature wear.
    ⚠Control arm bolts must be torqued with full vehicle weight on wheels. Torquing with suspension hanging will cause premature bushing failure.
    Torque spec

    Control Arm Bolts165 Nm (122 lb-ft)

Reassembly

1. Ensure all fasteners are tightened to specification with vehicle at ride height
2. Verify cotter pin is properly installed in ball joint castle nut if applicable
3. Check that no brake lines, ABS wiring, or other components were damaged during the procedure

Verification

• Test drive vehicle in a safe area at low speed, listening for any clunks or unusual noises from the rear suspension
• Perform a visual inspection under the vehicle to verify all bolts are secure and no components are contacting
• Schedule a professional four-wheel alignment as control arm replacement affects rear suspension geometry and tire wear

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