This procedure covers the replacement of worn or damaged trailing arm bushings on the rear suspension of a 2015-2020 Ford F-150 with 3.5L EcoBoost engine.

Warnings

Tools required

Parts

• Trailing arm bushing kit (front and rear per side) × 2 — Use OEM specification
• Optional: Trailing arm bolts × 4 — 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 on ground
4. Raise rear of vehicle and support with jack stands on frame rails
5. Remove rear wheels
6. Spray all trailing arm mounting bolts with penetrating lubricant and allow to soak

Procedure

1. 1

   Support rear axle assembly
   Position a hydraulic jack under the rear axle housing near the trailing arm to support the weight and maintain suspension geometry during disassembly. Raise jack until it just contacts the axle without lifting.
2. 2

   Remove shock absorber lower mounting bolt
   Locate the shock absorber lower mounting bolt connecting to the rear axle. Use a socket and breaker bar to remove the bolt completely. Allow the shock to hang freely or secure it with a bungee cord to prevent strain on the upper mount.
3. 3

   Disconnect sway bar link if equipped
   If vehicle is equipped with a rear sway bar, locate the sway bar end link connection to the trailing arm or axle. Hold the shaft with an Allen key to prevent rotation and remove the nut using a socket. Disconnect the link from the mounting point.
   Torque spec

   Sway Bar Link Nuts55 Nm (41 lb-ft)
4. 4

   Remove trailing arm frame mounting bolt
   Locate the front trailing arm mounting bolt where it attaches to the frame bracket. This is typically a large bolt with the bushing installed in the trailing arm eye. Use a socket and breaker bar to remove the bolt completely. Note the orientation and any washers or spacers.
5. 5

   Remove trailing arm axle mounting bolt
   Locate the rear trailing arm mounting bolt where it attaches to the axle housing bracket. Support the trailing arm with your hand or a strap as you remove this bolt. Once removed, carefully lower and remove the trailing arm from the vehicle.
6. 6

   Inspect trailing arm and bushings
   Clean the trailing arm thoroughly with a wire brush. Inspect for cracks, deformation, or damage. Check both front and rear bushing bores for damage or excessive wear. Note which bushing(s) require replacement - typically both front and rear bushings are replaced as a set.
7. 7

   Remove old bushings from trailing arm
   Using a hydraulic press or bushing removal tool, press out the old bushings from the trailing arm eyes. Apply pressure evenly and support the arm properly to prevent distortion. If bushings are stubborn, a bushing removal tool with receiving cups may be required. Clean the bores thoroughly after removal.
   ⚠Support trailing arm securely in press to prevent shifting. Apply pressure slowly and evenly to avoid damaging the arm.
8. 8

   Install new bushings
   Apply a light coating of soapy water or assembly lubricant to the new bushings (do not use petroleum-based lubricants on rubber bushings). Position the bushing squarely in the trailing arm bore, ensuring proper orientation if bushings are directional. Use the hydraulic press or installation tool to press the bushing in evenly until fully seated and flush with the arm.
   ℹ️Some bushings have orientation marks or voids that must align with load direction - consult bushing manufacturer instructions.
9. 9

   Install trailing arm to axle
   Position the trailing arm back into place on the vehicle. Start by aligning the rear bushing eye with the axle bracket. Insert the axle mounting bolt through the bracket and bushing but do not fully tighten yet - leave it finger tight plus a few turns. Use the jack to adjust axle position if needed for alignment.
10. 10

    Install trailing arm to frame
    Align the front bushing eye with the frame bracket. You may need to use a pry bar or adjust the jack height slightly to align the holes. Install the frame mounting bolt with any spacers or washers in their original positions. Thread the bolt in but do not fully tighten yet.
11. 11

    Reconnect sway bar link if equipped
    If vehicle has a rear sway bar, reconnect the sway bar end link to its mounting point. Hold the shaft with an Allen key and install the nut.
    Torque spec

    Sway Bar Link Nuts55 Nm (41 lb-ft)
12. 12

    Reinstall shock absorber lower mounting
    Align the shock absorber lower eye with the mounting bracket and install the lower mounting bolt. Torque to specification if provided, or tighten securely.
13. 13

    Install wheels and lower vehicle
    Install the rear wheels and thread lug nuts on by hand. Lower the vehicle until the tires just contact the ground but the suspension is still slightly unloaded. Torque the wheel lug nuts in a star pattern.
    Torque spec

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

    Final torque trailing arm bolts at ride height
    With the vehicle weight fully on the wheels at normal ride height, torque both the front frame mounting bolt and rear axle mounting bolt to specification. This is critical - trailing arm bushings must be torqued at ride height to prevent premature wear and binding. If control arm torque specification applies to trailing arm mounting bolts, use 165 Nm (122 lb-ft), otherwise torque to 200-250 Nm typical for trailing arm applications. Consult factory service manual for exact specification.
    ⚠Critical: Suspension bushings must be torqued with vehicle at ride height. Torquing while suspended will cause premature bushing failure.

Reassembly

1. Repeat entire procedure for opposite side if both sides require bushing replacement
2. Most technicians recommend replacing trailing arm bushings on both sides simultaneously for balanced suspension performance
3. Ensure all fasteners are torqued to specification at proper ride height

Verification

• Test drive vehicle and verify no clunking or abnormal noises from rear suspension
• Check that vehicle tracks straight with no pulling to either side
• Visually inspect all connections for proper seating and torque
• Schedule an alignment check if handling seems affected, though trailing arm bushings typically do not require alignment unless severely worn

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