This procedure covers the removal and installation of the front subframe assembly on a 2015-2020 Ford F-150 with the 3.5L EcoBoost V6 engine, including disconnecting suspension components, steering linkage, and engine/transmission mounts.

Warnings

Tools required

Parts

• Subframe assembly × 1 — Use OEM specification
• Subframe mounting bolts × 8 — Replace if corroded or damaged
• Ball joint castle nut × 2 — Replace cotter pins
• Sway bar link nuts × 2 — Replace if damaged

Preparation

1. Park vehicle on level surface and engage parking brake. Chock rear wheels securely.
2. Disconnect negative battery terminal to prevent electrical shorts during work.
3. Raise vehicle using floor jack at manufacturer-specified lift points and support on jack stands at frame rails behind subframe.
4. Remove front wheels using 21mm socket and store in safe location.
5. Spray all fasteners to be removed with penetrating oil and allow to soak for 15-30 minutes.
6. Take detailed photographs of subframe alignment and all mounting positions for reference during installation.
7. Position transmission jack or adjustable support under subframe center, but do not lift or bear weight yet.

Procedure

1. 1

   Disconnect sway bar links
   Locate sway bar end links connecting the sway bar to the lower control arms on both sides. Hold the shaft with an Allen key to prevent rotation and remove the lower link nuts using an 18mm socket. Swing sway bar links upward and secure out of the way with wire or zip ties.
   Torque spec

   Sway Bar Link Nuts55 Nm (41 lb-ft)
2. 2

   Remove steering rack mounting bolts
   Locate the steering rack mounting bolts that secure the rack to the subframe. There are typically 2-4 bolts depending on configuration. Remove these bolts using a 15mm socket and carefully lower the steering rack onto the subframe. Do not disconnect steering shaft or hydraulic lines. Support the rack to prevent it from hanging by the steering column coupling.
3. 3

   Disconnect lower ball joints
   Remove cotter pins from ball joint castle nuts on both sides. Using a 21mm socket, loosen and remove the ball joint nuts. Insert ball joint separator tool between the lower control arm and steering knuckle. Strike the tool with a hammer to separate the ball joint taper from the knuckle. The knuckle assembly will remain attached to the strut and upper control arm.
   ⚠Do not strike the ball joint stud directly as this can damage the threads. Use a proper ball joint separator tool.
   Torque spec

   Ball Joint Nut101 Nm (75 lb-ft)
4. 4

   Support engine and transmission
   Position a second floor jack with wood block or engine support fixture under the oil pan (protect pan with wood). Raise jack until it just contacts the engine without lifting. This will support the powertrain weight once subframe mounts are disconnected. Verify the jack is stable and positioned to prevent engine tipping.
   ⚠️The engine and transmission must be properly supported before removing subframe mounts. Failure to support the powertrain can result in catastrophic damage or injury.
5. 5

   Disconnect engine mount through-bolts
   Locate the engine mount through-bolts that pass through the subframe-mounted engine mounts on both sides. These are typically 18mm bolts. Remove both through-bolts completely. The engine weight will now be supported by the floor jack positioned in step 4.
6. 6

   Disconnect transmission mount
   Locate the transmission mount where it attaches to the subframe near the transmission tailshaft area. Remove the transmission mount bolts or through-bolt (typically 15mm or 18mm). Leave the mount attached to the transmission. The transmission weight is now supported by the engine support.
7. 7

   Remove front differential mounting bolts (if AWD)
   For AWD models only: locate and remove the front differential mounting bolts that attach the differential to the subframe. Support the differential with a strap or separate jack if necessary. For RWD models, skip this step.
8. 8

   Disconnect brake lines and ABS wiring from subframe
   Locate any brake line clips or brackets attached to the subframe. Remove clips or brackets to free the brake lines from the subframe. Disconnect ABS wheel speed sensor wiring from any subframe-mounted clips or retainers. Do not disconnect brake lines at fittings; simply unclip them from the subframe.
9. 9

   Position transmission jack under subframe
   Adjust the transmission jack or subframe support to make firm contact with the subframe center section. Raise slightly to bear the subframe weight, but do not lift the subframe. Verify the support is centered and stable. The subframe should be balanced on the jack.
   ⚠Ensure the transmission jack is rated for the subframe weight and is positioned to prevent tipping during removal.
10. 10

    Remove subframe mounting bolts
    Locate all subframe-to-frame mounting bolts (typically 4-8 bolts depending on configuration). Using a 21mm socket and breaker bar, remove all mounting bolts while supporting the subframe with the transmission jack. Start with the rear bolts first, then remove front bolts. Note any alignment dowels or shims for reinstallation. Keep bolts organized by position.
    ⚠️The subframe will become free once all bolts are removed. Ensure the transmission jack is securely supporting the full weight before removing the final bolts.
11. 11

    Lower and remove subframe assembly
    Slowly lower the transmission jack to drop the subframe away from the vehicle frame. Check for any remaining connections (wiring, hoses, or linkages) as you lower. Guide the subframe clear of the steering rack and other components. Once lowered sufficiently, roll the transmission jack with subframe out from under the vehicle. Inspect all mounting points and alignment pins on the frame.
12. 12

    Inspect and prepare new or repaired subframe
    Clean all mounting surfaces on the vehicle frame rails using a wire brush. Inspect frame rails for damage, cracks, or corrosion. If installing a new subframe, transfer any necessary components from the old subframe including control arm bushings, brackets, and heat shields. Apply anti-seize compound to bolt threads. Verify all alignment dowels are present in the frame.
13. 13

    Position and raise subframe into place
    Position the subframe assembly on the transmission jack and roll it into position under the vehicle. Carefully raise the subframe, aligning it with the frame mounting points and any alignment dowels or pins. Ensure steering rack remains properly positioned on the subframe. Raise until mounting holes are aligned but do not fully seat yet.
14. 14

    Install subframe mounting bolts
    Install all subframe mounting bolts finger-tight first to ensure proper alignment. Install front bolts first, then rear bolts. Once all bolts are started, tighten them in a cross-pattern sequence to pull the subframe evenly into position. Torque all subframe mounting bolts to specification using a torque wrench. Verify subframe is fully seated against frame rails.
    ℹ️If mounting bolt torque specification differs from the 31 Nm listed, consult factory service manual for subframe-specific torque values, as 31 Nm may apply to different mounting hardware.
    Torque spec

    Mounting Bolts31 Nm (23 lb-ft)
15. 15

    Reconnect powertrain mounts
    Install engine mount through-bolts on both sides and tighten to specification. Install transmission mount bolts and tighten to specification. For AWD models, reconnect front differential mounting bolts. Once all mounts are secured, carefully lower and remove the engine support jack.
16. 16

    Reconnect steering rack
    Raise the steering rack into position on the subframe and install mounting bolts. Tighten steering rack mounting bolts to specification. Verify steering shaft coupling is properly engaged and not binding.
17. 17

    Reconnect lower ball joints
    Clean ball joint tapers and steering knuckle bores. Position steering knuckles over ball joint studs and install castle nuts. Tighten ball joint nuts to specification using a torque wrench. Install new cotter pins through castle nuts and bend to secure. Verify cotter pins are properly installed and nuts cannot back off.
    Torque spec

    Ball Joint Nut101 Nm (75 lb-ft)
18. 18

    Reconnect sway bar links
    Position sway bar links and install lower nuts. Hold the shaft with an Allen key while tightening nuts to the specified torque to prevent twisting the link shaft.
    Torque spec

    Sway Bar Link Nuts55 Nm (41 lb-ft)
19. 19

    Reconnect brake lines and ABS wiring
    Reinstall all brake line clips and brackets to the subframe. Route ABS wiring through subframe-mounted clips and retainers. Ensure no lines or wiring are pinched, stretched, or in contact with sharp edges or moving components.
20. 20

    Install wheels and lower vehicle
    Reinstall front wheels and hand-tighten lug nuts in a star pattern. Lower vehicle until tires just contact the ground but weight is not fully on suspension. Torque wheel lug nuts to specification in a star pattern. Fully lower vehicle and remove jack stands.
    Torque spec

    Wheel Lug Nuts156 Nm (115 lb-ft)

Reassembly

1. After vehicle is fully lowered and weight is on wheels, the control arm bolts must be torqued to 165 Nm (122 lb-ft) with the vehicle at normal ride height as specified.
2. Reconnect negative battery terminal and verify no warning lights are illuminated on instrument cluster.
3. If any steering components were disturbed, a front-end alignment is mandatory before driving the vehicle.

Verification

• Start engine and verify it runs smoothly without excessive vibration from mounts.
• Turn steering wheel lock-to-lock while stationary to verify full range of motion with no binding or interference.
• Visually inspect all reinstalled components for proper positioning and torque.
• Test drive vehicle at low speed in a safe area and verify no unusual noises, vibrations, or handling issues.
• Perform four-wheel alignment at a qualified shop to ensure proper suspension geometry and tire wear characteristics.

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