This procedure covers the removal and replacement of the rear lower control arm on a 2021-2024 Ford F-150 with 3.5L EcoBoost engine, including ball joint separation and proper torque sequencing.

Warnings

Tools required

Parts

• Rear lower control arm × 1 — Use OEM specification
• Ball joint cotter pin × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake
2. Chock front wheels securely
3. Loosen rear wheel lug nuts while vehicle is still on ground
4. Raise rear of vehicle and support on jack stands at frame rails
5. Remove rear wheel on side being serviced

Procedure

1. 1

   Support the rear knuckle assembly
   Position a floor jack under the rear knuckle/hub assembly to support it. Raise jack just enough to slightly compress the suspension and relieve tension on the control arm. This prevents the assembly from dropping when control arm is disconnected.
2. 2

   Disconnect sway bar link if necessary
   If the sway bar link interferes with control arm access, remove the lower sway bar link nut. Hold the shaft with an Allen key to prevent spinning while loosening the nut. Move link out of the way.
   Torque spec

   Sway Bar Link71 Nm (52 lb-ft)
3. 3

   Remove ball joint cotter pin
   Locate the ball joint nut on the lower control arm where it connects to the knuckle. Use needle nose pliers to straighten and remove the cotter pin. Discard the old cotter pin as a new one will be installed.
4. 4

   Loosen ball joint nut
   Using a 21mm socket, loosen the ball joint nut but do not remove it completely yet. Leave the nut threaded on a few turns to prevent the ball joint from separating violently when pressure is released.
   ⚠Keep nut partially threaded to prevent sudden separation when using ball joint separator
5. 5

   Separate ball joint from knuckle
   Insert ball joint separator tool between the control arm and knuckle at the ball joint taper. Apply pressure with the separator tool to break the taper fit. You may need to tap the knuckle with a hammer while applying pressure. Once taper is broken, remove the ball joint nut completely.
6. 6

   Mark control arm mounting position
   Before removing control arm mounting bolts, note the orientation and position of any adjustment shims or cam bolts if present. This helps maintain alignment settings during reinstallation.
7. 7

   Remove front control arm mounting bolt
   Locate the front control arm mounting bolt that attaches to the frame or subframe. Using an 18mm socket and breaker bar, remove the bolt completely. Support the control arm as you remove this bolt.
8. 8

   Remove rear control arm mounting bolt
   Remove the rear control arm mounting bolt using an 18mm socket. Once both mounting bolts are removed, carefully lower and remove the control arm from the vehicle. The floor jack supporting the knuckle will prevent the suspension from dropping.
9. 9

   Clean mounting surfaces
   Use a wire brush to clean the control arm mounting points on the frame and the ball joint taper seat on the knuckle. Remove any rust, dirt, or debris to ensure proper seating of the new control arm.
10. 10

    Install new control arm to frame
    Position the new control arm into the mounting brackets. Insert the front and rear mounting bolts but only hand-tighten them at this stage. Do not torque these bolts yet - they must be torqued with vehicle weight on the wheels.
    ℹ️Control arm mounting bolts are torqued in final step with vehicle at ride height
11. 11

    Connect ball joint to knuckle
    Raise the floor jack slightly to align the ball joint stud with the hole in the knuckle. Insert the ball joint stud into the knuckle and thread on the ball joint nut. Tighten the nut to specification, then install a new cotter pin through the castle nut and ball joint stud. Bend the cotter pin ends to secure.
    Torque spec

    Ball Joint Nut101 Nm (75 lb-ft)
12. 12

    Reconnect sway bar link if removed
    If the sway bar link was disconnected, reconnect it to the control arm or appropriate mounting point. Hold the shaft with an Allen key and torque the nut to specification.
    Torque spec

    Sway Bar Link71 Nm (52 lb-ft)
13. 13

    Install wheel and lower vehicle
    Install the wheel and hand-tighten lug nuts. Lower the vehicle until the tires just touch the ground but the suspension is not fully loaded. Torque wheel lug nuts in a star pattern to specification. Then fully lower the vehicle to the ground.
    Torque spec

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

    Torque control arm bolts at ride height
    With the vehicle resting on the ground at normal ride height, torque both the front and rear control arm mounting bolts to specification. This is critical - torquing these bolts while suspended will preload the bushings and cause premature failure.
    ⚠Control arm bolts MUST be torqued with vehicle weight on wheels to prevent bushing damage
    Torque spec

    Control Arm Bolts165 Nm (122 lb-ft)

Reassembly

1. Ensure all fasteners are torqued to specification in the correct sequence
2. Verify new cotter pin is properly installed and bent to prevent backing out
3. Double-check that control arm mounting bolts were torqued at ride height, not while suspended

Verification

• Test drive vehicle at low speed and listen for any clunking or unusual noises from rear suspension
• Verify proper suspension travel and no binding through full range of motion
• Schedule a four-wheel alignment as control arm replacement affects rear suspension geometry
• Recheck all fastener torques after 50-100 miles of driving

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