This procedure covers the removal and replacement of the upper control arm on a 1970 AMC Rebel Machine, including ball joint separation and suspension disassembly.

Warnings

Tools required

Parts

• Upper control arm assembly × 1 — Use OEM specification or quality aftermarket equivalent
• Upper ball joint (if not included with control arm) × 1 — Use OEM specification
• Control arm bushings (if not pre-installed) × 2 — Use OEM specification
• Cotter pins × 2 — 1/8 inch diameter

Preparation

1. Park vehicle on level, solid surface and engage parking brake
2. Place wheel chocks behind rear wheels
3. Loosen front wheel lug nuts while vehicle is on ground
4. Raise front of vehicle and support securely on jack stands at frame rails
5. Remove front wheel on side being serviced
6. Spray all fasteners with penetrating oil and allow to soak for 15-20 minutes

Procedure

1. 1

   Support the lower control arm
   Position a floor jack under the lower control arm as close to the ball joint as possible. Raise the jack just enough to take light tension off the coil spring. This prevents the spring from forcing the knuckle downward when the upper ball joint is separated. The jack must remain in place throughout the procedure.
2. 2

   Remove brake caliper
   Remove the two bolts securing the brake caliper to the steering knuckle. Carefully lift the caliper off the rotor and support it with wire or a bungee cord to the frame. Do not let the caliper hang by the brake hose as this can damage the hose.
3. 3

   Remove upper ball joint cotter pin and castle nut
   Locate the upper ball joint stud where it connects to the steering knuckle. Straighten and remove the cotter pin using pliers. Remove the castle nut from the ball joint stud using the appropriate socket. Do not discard the nut yet as it may be needed to help separate the joint.
4. 4

   Separate upper ball joint from steering knuckle
   Using a ball joint separator or pickle fork, break the taper between the ball joint stud and the steering knuckle. Position the tool properly and strike sharply with a hammer, or use a tie rod puller to apply pressure. If using a pickle fork, be aware this will likely damage the ball joint boot. Once separated, the knuckle will pivot downward onto the lower control arm jack support.
   ⚠Keep hands clear as the joint may separate suddenly. Ensure the floor jack is supporting the lower control arm to prevent sudden drop.
5. 5

   Mark alignment shim location
   The upper control arm is adjusted using shims at the frame mounting points. Before removal, carefully note the position, quantity, and thickness of all shims at both the front and rear mounting bolts. Mark or photograph their locations. These shims control camber and caster settings.
6. 6

   Remove upper control arm front mounting bolt
   Locate the front mounting bolt that secures the upper control arm to the frame bracket. This bolt passes through the control arm bushings and frame. Hold the nut on the backside with a wrench while removing the bolt from the front with a socket. Remove the bolt, noting the position of any shims or washers.
7. 7

   Remove upper control arm rear mounting bolt
   Locate the rear mounting bolt that secures the upper control arm to the frame bracket. Hold the nut on the backside with a wrench while removing the bolt with a socket. Remove the bolt, keeping track of all shims and washers. The upper control arm can now be removed from the vehicle.
8. 8

   Inspect and clean mounting surfaces
   With the control arm removed, inspect the frame mounting brackets for damage, cracks, or excessive wear. Clean all mounting surfaces with a wire brush to remove rust, dirt, and old undercoating. Inspect the shims for damage and clean them as well. This ensures proper seating of the new control arm.
9. 9

   Install new upper control arm
   Position the new upper control arm into the frame brackets. Install the rear mounting bolt first, inserting it through the frame bracket, shims (in their original positions), control arm bushing, and opposite bracket. Thread the nut on but do not tighten yet. Repeat for the front mounting bolt with its shims in the original positions. Control arm bolts should be tightened with the vehicle at normal ride height.
10. 10

    Connect ball joint to steering knuckle
    With the floor jack still supporting the lower control arm, raise or lower the jack as needed to align the upper ball joint stud with the hole in the steering knuckle. Insert the ball joint stud through the knuckle. Install the castle nut and tighten firmly until snug. Align the castle nut slots with the hole in the stud and install a new cotter pin. Bend the cotter pin ends to secure.
11. 11

    Tighten control arm mounting bolts
    With the ball joint connected and the suspension at or near normal ride height (jack supporting lower control arm), tighten both the front and rear upper control arm mounting bolts. These should be torqued to manufacturer specifications, typically in the 75-85 ft-lbs range, though verify this specification before final tightening.
12. 12

    Reinstall brake caliper
    Remove the support wire from the brake caliper. Position the caliper over the brake rotor and align the mounting holes with the steering knuckle. Install the two caliper mounting bolts and tighten securely.
13. 13

    Remove jack and reinstall wheel
    Carefully lower and remove the floor jack from under the lower control arm. The suspension should now support itself properly. Reinstall the wheel and thread on all lug nuts by hand. Lower the vehicle until the tire just touches the ground, then torque the lug nuts in a star pattern to 75-80 ft-lbs. Fully lower the vehicle and remove jack stands.

Reassembly

1. Ensure all fasteners are tightened to specification with control arm bolts torqued at normal ride height
2. Verify new cotter pin is properly installed and bent at ball joint
3. Double-check that brake caliper is secure and brake hose is not twisted or kinked
4. Repeat entire procedure for opposite side if replacing both upper control arms

Verification

• Test drive vehicle at low speed in a safe area and verify no unusual noises from suspension
• Check for proper steering response and ensure wheel returns to center normally
• Inspect for any fluid leaks around brake caliper area
• Schedule a professional wheel alignment as soon as possible, as camber and caster settings have been disturbed
• After 50-100 miles, re-torque control arm mounting bolts and verify ball joint cotter pin is secure

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