Ball Joints - Upper and Lower

This procedure covers the removal and replacement of both upper and lower ball joints on the front suspension of a 1970 AMC Rebel Machine.

Warnings

Tools required

Parts

• Upper ball joint (driver side) × 1 — Use OEM specification
• Upper ball joint (passenger side) × 1 — Use OEM specification
• Lower ball joint (driver side) × 1 — Use OEM specification
• Lower ball joint (passenger side) × 1 — Use OEM specification
• Cotter pins (assorted) × 8 — 1/8 inch diameter
• Wheel bearing grease × 1 — NLGI Grade 2

Preparation

1. Park vehicle on level, solid surface and set parking brake
2. Chock rear wheels securely
3. Loosen front wheel lug nuts while vehicle is on ground
4. Raise front of vehicle and support with jack stands under frame rails behind lower control arms
5. Remove front wheels completely
6. Spray all ball joint fasteners, castle nuts, and control arm bolts with penetrating oil

Procedure

1. 1

   Support lower control arm
   Position a floor jack under the lower control arm as close to the ball joint as possible. Raise jack just enough to slightly compress the coil spring and support the control arm weight. This is critical for safety and will allow controlled release of spring tension later.
2. 2

   Disconnect upper ball joint from spindle
   Remove the cotter pin from the upper ball joint castle nut. Using a wrench, loosen but do not fully remove the castle nut (leave it threaded on 2-3 turns). Using a ball joint separator or pickle fork, break the taper between the upper ball joint stud and the steering knuckle. Once separated, remove the castle nut completely and lift the upper control arm away from the knuckle.
3. 3

   Disconnect lower ball joint from spindle
   Remove the cotter pin from the lower ball joint castle nut. Loosen but do not remove the castle nut (leave it threaded on 2-3 turns for safety). Use the ball joint separator to break the taper between the lower ball joint stud and the steering knuckle. Once separated, carefully lower the floor jack slightly to relieve spring pressure, then remove the castle nut. Pivot the spindle/knuckle assembly out of the way.
4. 4

   Remove upper ball joint from control arm
   The upper ball joint on the AMC Rebel is riveted to the upper control arm from the factory. Use a drill with a 1/4 inch bit to drill out the rivet heads, then use a punch to drive out the rivet bodies. Clean the mounting surface on the control arm with a wire brush. The replacement ball joint will use bolts and nuts provided in the kit instead of rivets.
5. 5

   Install new upper ball joint
   Position the new upper ball joint onto the upper control arm, aligning the bolt holes. Insert the mounting bolts from the top (ball joint stud pointing down) and thread on the lock nuts from beneath. Tighten the bolts in a crisscross pattern. Note: Consult the ball joint manufacturer specifications for torque values as factory specs are unavailable.
6. 6

   Remove lower ball joint from control arm
   The lower ball joint is press-fit into the lower control arm. Use a ball joint press kit with the appropriate receiving cup and driver adapters. Position the receiving cup under the lower ball joint and the driver on top. Tighten the press slowly and evenly until the old ball joint is pushed out of the control arm. If the joint is seized, apply heat around the control arm boss (not the ball joint itself) to expand the metal.
7. 7

   Prepare control arm for new lower ball joint
   Clean the ball joint bore in the lower control arm thoroughly with a wire brush and solvent. Inspect the bore for cracks, elongation, or damage. The bore must be clean and free of debris for proper press-fit of the new ball joint. Check that the new ball joint fits snugly but can be started into the bore by hand.
8. 8

   Press in new lower ball joint
   Position the new lower ball joint into the control arm bore, ensuring it is properly aligned and the stud points downward. Use the ball joint press with appropriate adapters to press the new joint into place. Press until the ball joint is fully seated and bottomed in the control arm. The joint should be flush or slightly recessed per manufacturer specifications.
9. 9

   Reconnect lower ball joint to spindle
   Raise the floor jack under the lower control arm to bring the lower ball joint stud up to the steering knuckle. Guide the stud through the hole in the knuckle. Thread on the castle nut and tighten firmly. Align the castle nut slots with the stud hole and install a new cotter pin, bending the ends to secure.
10. 10

    Reconnect upper ball joint to spindle
    Position the steering knuckle so the upper ball joint stud can be inserted through the upper mounting hole. Thread on the castle nut and tighten firmly. Align the castle nut slots with the stud hole and install a new cotter pin, bending the ends to secure. The spindle should now be captured between the upper and lower ball joints.
11. 11

    Torque all fasteners and lubricate
    Using a torque wrench, torque the upper ball joint mounting bolts (if adjustable) and both castle nuts to specifications. Since factory torque values are not available in the database, consult the replacement ball joint manufacturer specifications. Most AMC applications require 75-85 ft-lbs for ball joint castle nuts. After torquing, verify cotter pins are properly installed. Lubricate both ball joints through the grease fittings using a grease gun until fresh grease appears at the boot seals.
12. 12

    Repeat for opposite side
    Carefully lower the jack from under the control arm. Repeat steps 1 through 11 for the opposite side of the vehicle, replacing all four ball joints for balanced suspension performance and safety.

Reassembly

1. Reinstall both front wheels and hand-tighten lug nuts in a star pattern
2. Lower vehicle until wheels just touch ground, then torque lug nuts to specification (typically 75-80 ft-lbs for 1970 AMC)
3. Fully lower vehicle and remove jack stands
4. Bounce front end several times to settle suspension components
5. Recheck all ball joint castle nuts for proper torque and verify cotter pins are secure

Verification

• Start vehicle and turn steering wheel lock-to-lock while stationary to verify no binding or unusual noises
• Test drive at low speed in a safe area and verify normal steering feel with no clunking or looseness
• Perform visual inspection of all ball joint boots for proper seating and no tears
• Check that all cotter pins are properly installed and bent
• Schedule a professional front-end alignment as ball joint replacement affects camber and caster settings

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