Subframe

Complete removal and replacement of the front subframe assembly on a 1972 Ford F-100, including disconnection of steering linkage, engine mounts, and suspension components.

Warnings

Tools required

Parts

• Subframe assembly × 1 — Use OEM specification or aftermarket equivalent
• Engine mount insulators × 2 — D2TZ-6038-A
• Subframe mounting bolts × 1 — Grade 8 hardware kit
• Cotter pins (assorted) × 10 — Use OEM specification
• Lock washers (assorted) × 12 — Use OEM specification

Preparation

1. Park vehicle on level concrete surface and chock rear wheels securely
2. Disconnect negative battery cable
3. Apply penetrating oil to all subframe bolts, suspension fasteners, and steering components; allow to soak minimum 2 hours (ideally overnight)
4. Raise vehicle and support on jack stands at frame rails behind the subframe area, ensuring minimum 36 inches of clearance
5. Remove both front wheels
6. Place additional jack stands under rear axle to prevent vehicle from tipping
7. Mark alignment reference points on steering components with paint marker
8. Photograph all component positions and shim locations for reassembly reference

Procedure

1. 1

   Install engine support
   Install an engine support bar across the fender wells or attach an engine hoist to the engine lift points. The support must independently carry the full weight of the engine and transmission. Adjust support to just barely take tension, leaving minimal weight on the engine mounts. Verify stability by gently pushing on the engine.
2. 2

   Disconnect steering linkage at Pitman arm
   Locate the Pitman arm connection to the center link at the steering box output shaft. Remove the cotter pin from the Pitman arm castle nut. Using a wrench, remove the castle nut. Install the Pitman arm puller and tighten the forcing screw to separate the Pitman arm from the center link. Do not strike the puller with a hammer as this can damage the steering box. Once separated, swing the center link away from the frame.
3. 3

   Disconnect tie rod ends from spindles
   At each front spindle, remove the cotter pin from the tie rod end castle nut. Remove the castle nuts from both outer tie rod ends. Use a tie rod end puller or ball joint separator to break the taper free from the spindle arms. Support the center link with wire or a bungee cord to prevent strain on the remaining connections.
4. 4

   Disconnect upper control arms from frame
   On each side, locate the upper control arm-to-frame pivot bolts (typically 2 bolts per side through rubber bushings). Remove the 2 bolts securing each upper control arm to the frame crossmember. The control arms will remain attached to the spindles via ball joints but will be free from the frame. Allow the suspension to hang.
5. 5

   Disconnect lower control arm ball joints from spindles
   Remove the cotter pin and castle nut from each lower ball joint at the spindle. Use a ball joint separator or pickle fork to break the taper connection. Once separated, the spindle and upper control arm assembly will be free to swing upward. Secure the spindle assembly with wire or rope to the frame to prevent it from hanging on the brake hose.
6. 6

   Disconnect shock absorbers
   Remove the lower shock absorber mounting bolt on each side where the shock attaches to the lower control arm or shock tower on the subframe. The upper shock mount will remain attached to the frame. Allow the shocks to hang or remove them completely if preferred.
7. 7

   Disconnect front sway bar (if equipped)
   If equipped with a front sway bar, remove the sway bar end link bolts connecting the bar to the lower control arms. Remove the 2 sway bar frame bracket bolts on each side. The sway bar will remain with the subframe during removal.
8. 8

   Disconnect engine mounts from subframe
   On each side of the engine, locate the engine mount-to-subframe through-bolts. These pass horizontally through the frame-mounted portion of the engine mount. Remove 1 through-bolt per side. The engine will now be supported entirely by the engine support bar or hoist. Verify the support is secure before proceeding.
9. 9

   Support subframe with transmission jack
   Position a transmission jack or equivalent under the center of the subframe. Raise the jack until it contacts the subframe firmly and takes slight pressure. Use wooden blocks or jack adapters to distribute the load across the subframe width. Secure the subframe to the jack with chains or ratchet straps to prevent shifting during removal.
10. 10

    Remove subframe-to-frame mounting bolts
    Locate the 6 bolts securing the subframe to the main vehicle frame. There are typically 4 bolts at the front of the subframe (2 per side through the front crossmember) and 2 bolts at the rear where the subframe meets the frame rails. Note any shims between the subframe and frame; mark their locations. Using a breaker bar and socket, remove all 6 mounting bolts. Keep shims organized by location.
11. 11

    Lower and remove subframe assembly
    With all mounting bolts removed and the subframe secured to the jack, slowly and evenly lower the transmission jack. Guide the subframe as it descends to ensure it clears the steering box, frame rails, and any brake or fuel lines. Lower the assembly completely to the ground and roll it out from under the vehicle. The subframe will have the lower control arms, coil springs, and steering components still attached.
12. 12

    Inspect and prepare new subframe
    If installing a replacement subframe, transfer any reusable components from the old subframe to the new one, including lower control arms, springs, and steering components as needed. Inspect mounting surfaces on the vehicle frame for damage, corrosion, or deformation. Wire brush all mounting surfaces clean. Install new shims in their original locations on the new subframe.
13. 13

    Install new subframe assembly
    Secure the new subframe to the transmission jack with chains. Roll the jack under the vehicle and align the subframe approximately with the frame rails. Slowly raise the jack, guiding the subframe into position. Align all 6 mounting bolt holes with the frame. Thread all 6 mounting bolts by hand to ensure proper alignment before tightening any bolts.
14. 14

    Torque subframe mounting bolts
    Tighten the 6 subframe-to-frame mounting bolts in a cross-pattern sequence: front driver, rear passenger, front passenger, rear driver, then remaining two bolts. Since factory torque specifications are not available in the database, consult a Ford service manual for the correct torque value (typically 65-85 ft-lbs for this application). Verify all shims remained in position during installation.
15. 15

    Reconnect engine mounts
    Install new engine mount insulators if the originals show cracking or deterioration. Lower the engine slightly onto the subframe-mounted portions of the engine mounts. Install the engine mount through-bolts on both sides. Consult a factory Ford service manual for the proper torque specification before tightening. Remove the engine support bar or hoist only after verifying mount installation.
16. 16

    Reconnect lower suspension and steering
    Reconnect the lower ball joints to the spindles, installing new castle nuts and cotter pins. Reconnect the lower shock mounts with new lock washers. If equipped, reinstall the sway bar brackets and end links. Reconnect the upper control arms to the frame with their pivot bolts. Reconnect tie rod ends to spindles with new castle nuts and cotter pins. Reconnect the Pitman arm to the center link with a new castle nut and cotter pin.

Reassembly

1. Reinstall front wheels and torque lug nuts to specification (typically 85-95 ft-lbs for 1972 F-100)
2. Lower vehicle to ground
3. Reconnect negative battery cable
4. Start engine and verify no unusual vibrations or noises from engine mounts
5. Test steering through full lock-to-lock motion to verify clearances
6. Check for any fluid leaks around disturbed components

Verification

• Perform a complete visual inspection of all reconnected components to ensure nothing was missed
• Bounce each front corner of the vehicle to verify suspension operation and listen for unusual noises
• With vehicle on ground, verify proper ride height and that shims maintained alignment geometry
• Test drive at low speed in a safe area, checking for steering responsiveness, unusual vibrations, or pulling
• Have a professional front-end alignment performed immediately, as removal of steering and suspension components will have significantly altered alignment settings

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