Replace worn radius arm bushings on the front suspension of a 2015-2020 Ford F-150 with 5.0L V8 to restore handling and eliminate clunking noises.

Warnings

Tools required

Parts

• Radius arm bushings (front and rear per side) × 2 — Use OEM specification
• Cotter pins for ball joint nuts × 2 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake
2. Loosen front wheel lug nuts while vehicle is on ground
3. Raise front of vehicle and support frame on jack stands rated for vehicle weight
4. Remove front wheel on side being serviced
5. Spray all radius arm mounting bolts and ball joint nut with penetrating oil, allow to soak 15-20 minutes
6. Place a floor jack under the lower control arm near the ball joint to support suspension weight

Procedure

1. 1

   Disconnect sway bar link
   Locate the sway bar link connecting to the lower control arm. Use an Allen key to hold the shaft while removing the upper nut with a wrench. Swing the sway bar link out of the way.
   Torque spec

   Sway Bar Link76 Nm (56 lb-ft)
2. 2

   Remove ball joint cotter pin and nut
   Straighten and remove the cotter pin from the ball joint castle nut on the radius arm. Remove the castle nut completely but keep the nut nearby for reference. Do not reuse the old cotter pin.
   Torque spec

   Ball Joint Nut110 Nm (81 lb-ft)
3. 3

   Separate ball joint from spindle
   Insert a ball joint separator or pickle fork between the radius arm ball joint and the steering knuckle/spindle. Strike the tool with a hammer to break the taper joint free. Once separated, support the radius arm with the floor jack to prevent it from dropping.
   ⚠Ball joint may separate suddenly; ensure floor jack is positioned to catch the radius arm
4. 4

   Remove front radius arm mounting bolt
   Locate the front radius arm mounting bolt at the frame bracket. This is typically a large horizontal bolt through the front bushing. Use a breaker bar and socket to remove this bolt completely. The radius arm will now pivot on the rear mount only.
5. 5

   Remove rear radius arm mounting bolt
   Locate the rear radius arm mounting bolt at the frame bracket. Remove this bolt while supporting the radius arm with the floor jack. Once removed, carefully lower the radius arm and remove it from the vehicle.
6. 6

   Inspect and clean radius arm
   Inspect the radius arm for cracks, bends, or damage. Use a wire brush to clean the bushing bore areas thoroughly, removing all rust and debris. Check ball joint for excessive play or torn boot; if damaged, radius arm replacement may be necessary.
7. 7

   Press out old bushings
   Using a hydraulic press or bushing press tool set, press out the old front and rear bushings from the radius arm. Note the orientation of any offset bushings before removal. Apply steady pressure until bushings are completely removed. Clean the bores again after bushing removal.
   ⚠Wear safety glasses when operating hydraulic press; old bushings can fragment during removal
8. 8

   Press in new bushings
   Position new bushings in the correct orientation (match original installation or follow bushing manufacturer markings). Using the hydraulic press, carefully press new bushings into the radius arm bores until fully seated and flush with the arm. Ensure bushings are straight during installation to prevent binding.
9. 9

   Install radius arm to frame mounts
   Position the radius arm back into the vehicle, aligning the front and rear bushing holes with the frame bracket mounting points. Insert both mounting bolts finger-tight. Do not torque at this time as bushings must be torqued at ride height.
10. 10

    Connect ball joint to spindle
    Raise the radius arm using the floor jack to align the ball joint stud with the hole in the steering knuckle/spindle. Insert the ball joint stud through the knuckle. Install the castle nut and torque to specification. Align the castle nut slots with the ball joint stud hole and install a new cotter pin. Bend cotter pin ends to secure.
    ℹ️If castle nut slots do not align with cotter pin hole, tighten nut further up to 1/6 turn; never loosen to align
    Torque spec

    Ball Joint Nut110 Nm (81 lb-ft)
11. 11

    Reconnect sway bar link
    Position the sway bar link back to the lower control arm mounting point. Install the nut while holding the shaft with an Allen key. Torque to specification.
    Torque spec

    Sway Bar Link76 Nm (56 lb-ft)
12. 12

    Install wheel and lower vehicle to load suspension
    Install the wheel and hand-tighten lug nuts. Lower the vehicle until the suspension is at normal ride height with full vehicle weight on the wheels, but keep the jack stands in place as a safety backup. This loads the bushings in their normal operating position.
13. 13

    Torque radius arm mounting bolts at ride height
    With the vehicle at ride height and weight on the suspension, torque both the front and rear radius arm frame mounting bolts to specification. This is critical as torquing bushings while unloaded will cause premature bushing failure.
    ⚠Radius arm bushings MUST be torqued at ride height to prevent binding and premature wear
14. 14

    Final wheel installation
    Raise vehicle slightly to remove jack stands. Lower vehicle completely to the ground. Torque wheel lug nuts to specification in a star pattern.
    Torque spec

    Wheel Lug Nuts169 Nm (125 lb-ft)

Reassembly

1. If servicing both sides, repeat entire procedure for opposite side
2. Radius arm mounting bolts must always be torqued with vehicle weight on suspension
3. Always use new cotter pins for ball joint castle nuts

Verification

• Test drive vehicle at low speed and verify no clunking or abnormal noises from front suspension
• Perform visual inspection under vehicle to confirm all fasteners are tight and cotter pins are properly installed
• Check for proper suspension movement and ensure no binding during full steering lock in both directions
• Schedule a professional alignment as radius arm removal affects front suspension geometry

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