Upper Control Arm - Rear

This procedure covers the removal and replacement of the rear upper control arm on a 1972 Ford F-100 with 302ci V8, including suspension disassembly and reassembly.

Warnings

Tools required

Parts

• Upper control arm assembly × 1 — Use OEM specification
• Upper control arm bushings (if not included with arm) × 2 — Use OEM specification
• Upper ball joint (if not included with arm) × 1 — Use OEM specification
• Cotter pin for ball joint stud × 1 — 1/8 inch

Preparation

1. Park vehicle on level ground and engage parking brake
2. Place wheel chocks in front of front wheels
3. Loosen rear wheel lug nuts while vehicle is on the ground
4. Raise rear of vehicle using floor jack at rear axle housing
5. Support vehicle on jack stands placed under frame rails
6. Remove rear wheel on the side being serviced
7. Leave floor jack under axle housing with slight upward pressure to support axle weight
8. Spray all control arm mounting bolts and ball joint stud nut with penetrating oil and allow to soak for 10-15 minutes

Procedure

1. 1

   Remove upper ball joint stud nut
   Locate the upper control arm ball joint connection at the axle housing. Remove the cotter pin from the ball joint stud castle nut. Using an appropriate size socket, remove the castle nut from the ball joint stud. Do not discard the nut yet as it may be needed to press the stud from the taper.
2. 2

   Separate ball joint from axle housing
   Insert a ball joint separator (pickle fork) between the ball joint stud and the axle housing mounting point. Strike the separator with a hammer to break the taper fit. Alternatively, reinstall the castle nut flush with the top of the stud and strike the mounting ear on the axle housing with a hammer while applying upward pressure on the control arm to shock the taper loose. Once separated, remove the castle nut completely.
3. 3

   Remove frame-side mounting bolt
   Locate the front mounting point where the upper control arm attaches to the frame rail. This is typically a single through-bolt with nut. Using a wrench to hold the bolt head and a socket on the nut, remove the mounting bolt completely. Note the orientation of any washers or spacers for reinstallation.
4. 4

   Remove axle-side mounting bolt
   Locate the rear mounting point where the upper control arm attaches to the axle housing bracket. Using a wrench to hold the bolt head and a socket on the nut, remove the mounting bolt completely. The control arm should now be free from the vehicle.
5. 5

   Inspect mounting points and clean
   Inspect the frame rail and axle housing mounting points for damage, cracks, or excessive wear. Clean all mounting surfaces with a wire brush and brake cleaner to remove rust, dirt, and old grease. Inspect the mounting bolt holes for wallowing or elongation that would indicate worn bushings or improper torque.
6. 6

   Install new upper control arm to frame
   Position the new upper control arm at the frame rail mounting point. Insert the mounting bolt through the frame bracket and control arm bushing in the same orientation as removed. Install any washers or spacers in their original positions. Thread the nut onto the bolt but do not tighten completely at this time. The suspension must be at normal ride height before final torque is applied.
7. 7

   Connect ball joint to axle housing
   Align the ball joint stud with the mounting hole in the axle housing. You may need to use a pry bar to shift the axle slightly or adjust the floor jack height to align the holes. Insert the ball joint stud into the axle housing taper and thread the castle nut onto the stud.
8. 8

   Torque ball joint castle nut
   Tighten the ball joint castle nut to specification. Continue tightening only as much as needed to align the next castle slot with the cotter pin hole in the stud. Install a new cotter pin and bend the legs to secure. Since specific torque value is not provided in the database, tighten to 70-90 ft-lbs as typical for this application, then advance to next castle slot if needed for cotter pin alignment.
9. 9

   Install axle-side mounting bolt
   Insert the mounting bolt through the axle housing bracket and control arm rear bushing. Thread the nut onto the bolt but do not tighten to final torque at this time.
10. 10

    Load suspension to ride height
    Using the floor jack, raise the rear axle to simulate normal ride height. This positions the control arm bushings in their neutral state before final torque. The vehicle should be at approximately the same height as when resting on the ground with normal load.
11. 11

    Torque control arm mounting bolts
    With the suspension at ride height, torque the frame-side mounting bolt to specification, then torque the axle-side mounting bolt to specification. 66.0 lb-ft (90.0 Nm) Lower the floor jack slightly but maintain support under the axle. Verified detail (Exact torque specification for upper control arm frame-side and axle-side mounting bolts on 1972 Ford F-100 rear suspension): 66.0 lb-ft (90.0 Nm)
12. 12

    Reinstall wheel
    Reinstall the rear wheel and thread the lug nuts by hand. Tighten the lug nuts in a star pattern until snug but do not torque yet.
13. 13

    Lower vehicle and final torque
    Remove the jack stands and lower the vehicle to the ground. With the vehicle weight on all wheels, torque the wheel lug nuts to the OEM specification (typically 85-100 ft-lbs for a 1972 F-100) in a star pattern.

Reassembly

1. Reassembly is covered in the main procedure steps
2. Ensure all fasteners are torqued with suspension at ride height to prevent premature bushing failure
3. Do not grease ball joint unless equipped with grease fitting

Verification

• Start vehicle and turn steering wheel full lock in both directions to verify no binding or interference
• Test drive vehicle at low speed and verify no unusual noises from rear suspension
• Verify no clunking or knocking sounds over bumps
• Check ball joint stud cotter pin is properly installed and secured
• Re-torque all fasteners after 50-100 miles of driving
• Have alignment checked if vehicle pulls or handling has changed

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