Ball Joint - Upper

Replace the upper ball joint on a 1970 AMC Rebel Machine, requiring disassembly of the front suspension components and pressing out the old ball joint.

Warnings

Tools required

Parts

• Upper ball joint × 1 — Use OEM specification or K772 equivalent
• Cotter pin for castle nut × 1 — 1/8" diameter

Preparation

1. Park vehicle on level surface and apply parking brake
2. Place wheel chocks behind rear wheels
3. Loosen lug nuts on the wheel where upper ball joint will be replaced while vehicle is on ground
4. Raise front of vehicle with floor jack at factory jacking point
5. Support vehicle securely on jack stands placed under frame rails
6. Remove wheel and tire assembly
7. Spray all fasteners with penetrating oil and allow to soak for 10-15 minutes

Procedure

1. 1

   Support lower control arm
   Position floor jack under the lower control arm near the ball joint to support the weight of the control arm and compress the coil spring. Raise jack just enough to support the arm but not lift the vehicle.
2. 2

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

   Remove cotter pin and castle nut
   Remove the cotter pin from the upper ball joint castle nut. Discard the old cotter pin. Using appropriate socket, loosen but do not completely remove the castle nut from the upper ball joint stud. Leave nut on a few threads to prevent sudden separation.
4. 4

   Separate ball joint from steering knuckle
   Using a ball joint separator tool (pickle fork or appropriate puller), position tool between the upper control arm and steering knuckle at the ball joint taper. Strike tool with hammer or apply pressure to break the taper fit. Once taper is broken, remove castle nut completely and separate the knuckle from the upper ball joint stud.
   ⚠The steering knuckle may drop suddenly when ball joint separates. Ensure jack is properly supporting lower control arm.
5. 5

   Access upper ball joint rivets or bolts
   Pull steering knuckle outward and downward to provide access to upper control arm. If ball joint is riveted from factory, locate the rivet heads on top of the upper control arm. If previously replaced, it will have bolts and nuts.
6. 6

   Remove factory rivets or replacement bolts
   For factory rivets: Using a 1/4" or 5/16" drill bit, drill out the rivet heads, then drive out rivet shanks with a punch and hammer. For replacement bolts: Remove nuts and bolts securing ball joint to upper control arm. Remove old ball joint from control arm.
   ℹ️Factory ball joints are riveted. Replacement ball joints use bolts and nuts which are typically included with the new ball joint.
7. 7

   Clean mounting surface
   Use wire brush to clean the ball joint mounting surface on the upper control arm. Remove all rust, old paint, and debris to ensure proper seating of new ball joint.
8. 8

   Install new upper ball joint
   Position new upper ball joint on upper control arm with stud pointing downward. Align bolt holes in ball joint with holes in control arm. Insert bolts from top down through control arm and ball joint. Install nuts on bottom side and tighten bolts to secure ball joint to control arm. Torque bolts to manufacturer specification (typically 35-45 ft-lbs if not specified).
9. 9

   Reconnect steering knuckle to ball joint
   Guide steering knuckle back into position and align hole in knuckle with ball joint stud. Insert stud through knuckle. Install castle nut on ball joint stud and tighten while ensuring stud does not spin. Torque castle nut to specification (typically 50-75 ft-lbs for AMC applications).
10. 10

    Install new cotter pin
    Align castle nut slots with hole in ball joint stud. If slots don't align, tighten nut slightly until next slot aligns (never loosen to align). Insert new cotter pin through stud hole and bend ends to secure.
    ⚠Never loosen castle nut to align cotter pin hole. Always tighten to next alignment point.
11. 11

    Reinstall brake caliper
    Remove wire or support holding brake caliper. Position caliper over brake rotor and align mounting holes. Install caliper mounting bolts and torque to specification (typically 35-45 ft-lbs).
12. 12

    Remove jack and install wheel
    Carefully lower and remove floor jack from under lower control arm. Install wheel and tire assembly. Thread lug nuts by hand to prevent cross-threading, then snug with wrench.

Reassembly

1. Lower vehicle to ground and torque lug nuts to 75-85 ft-lbs in star pattern
2. Remove jack stands and lower vehicle completely
3. Pump brake pedal several times to ensure proper caliper position before driving

Verification

• Check that castle nut is properly torqued and cotter pin is securely installed
• Grasp tire at top and bottom and attempt to rock in and out - there should be no play in the upper ball joint
• Visually inspect that all fasteners are tight and brake caliper is properly secured
• Test drive vehicle at low speed and verify steering feels normal with no unusual noises or vibrations
• Have front end alignment checked and adjusted as ball joint replacement affects camber and caster settings

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