Ball Joint - Lower

This procedure covers the removal and replacement of the lower ball joint on a 1970 AMC Rebel Machine, requiring suspension disassembly and press work or ball joint service tools.

Warnings

Tools required

Parts

• Lower ball joint × 1 — Use OEM specification for AMC or quality aftermarket equivalent
• Cotter pin × 1 — 1/8 inch diameter
• Lower control arm bushing set (inspect) × 1 — Replace if worn

Preparation

1. Park vehicle on level surface and engage parking brake
2. Chock rear wheels securely
3. Loosen front wheel lug nuts while vehicle is on ground
4. Raise front of vehicle with floor jack at manufacturer recommended lift point
5. Support vehicle securely on jack stands placed under frame rails
6. Remove front wheel on side being serviced
7. Spray all fasteners with penetrating oil and allow to soak for 15-20 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 spring assembly. Raise jack just enough to take the load but not lift the vehicle. This prevents the control arm from dropping suddenly when the ball joint is disconnected.
2. 2

   Remove brake caliper
   Remove the two bolts securing the brake caliper to the steering knuckle. Support the caliper with wire or a bungee cord to prevent strain on the brake hose. Do not let the caliper hang by the brake line.
3. 3

   Remove cotter pin and castle nut
   Locate the lower ball joint stud at the steering knuckle. Remove and discard the cotter pin from the castle nut. Use a socket and breaker bar to remove the castle nut from the ball joint stud. Keep the nut accessible as you may need to thread it back on partially for separation.
4. 4

   Separate ball joint from steering knuckle
   Use a ball joint separator tool (pickle fork or puller-style) to break the taper fit between the ball joint stud and steering knuckle. If using a pickle fork, position it between the control arm and knuckle, then strike firmly with a hammer. If using a puller, follow manufacturer instructions. The joint will separate suddenly when the taper breaks free.
   ⚠Stand clear of the separation point - tool may slip or joint may separate violently
5. 5

   Lower control arm and remove knuckle clearance
   Slowly lower the floor jack supporting the control arm to create working clearance. The steering knuckle assembly will pivot upward. Ensure brake components and ABS wiring (if equipped) are clear and not binding.
6. 6

   Access lower ball joint mounting
   Inspect the lower control arm to identify the ball joint mounting style. On 1970 AMC Rebel models, the lower ball joint is typically press-fit into the lower control arm. If riveted, drill out rivets using a 1/4 inch drill bit and remove rivet remnants. Clean the mounting area with a wire brush.
7. 7

   Press out old ball joint
   Position the lower control arm in a ball joint press or shop press. Select the appropriate receiving cup adapter that fits around the ball joint housing and a driver adapter that contacts only the ball joint body (not the stud). Apply steady pressure to press the old ball joint out of the control arm. If using a C-frame press on the vehicle, position it to push the ball joint downward out of the arm.
   ⚠Ensure adapters are properly seated to prevent slipping under high pressure
8. 8

   Clean ball joint bore
   Use a wire brush and clean rag to thoroughly clean the ball joint bore in the control arm. Remove all rust, debris, and old material. Inspect the bore for damage, cracks, or excessive wear. If the bore is damaged, the control arm must be replaced.
9. 9

   Press in new ball joint
   Position the new ball joint in the control arm bore with the stud facing the correct direction (toward the steering knuckle). Use the ball joint press with appropriate adapters to press the new joint into place. Press until the ball joint is fully seated - you should feel resistance increase significantly when it bottoms out. Ensure the joint is pressed in squarely and sits flush with the control arm.
10. 10

    Reinstall steering knuckle to ball joint
    Raise the floor jack to lift the lower control arm and align the ball joint stud with the hole in the steering knuckle. You may need to use a pry bar to position the knuckle. Guide the stud through the knuckle hole and install the castle nut hand-tight.
11. 11

    Torque castle nut and install cotter pin
    Torque the lower ball joint castle nut to manufacturer specification (typically 75-90 ft-lbs for AMC applications - verify with service manual). Align the castle nut slots with the hole in the ball joint stud. If necessary, tighten the nut slightly more to align (never loosen). Install a new cotter pin and bend the ends to secure.
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 caliper mounting bolts and torque to specification (typically 35-45 ft-lbs).
13. 13

    Remove jack and reinstall wheel
    Carefully lower and remove the floor jack from under the control arm. Reinstall the wheel and thread lug nuts hand-tight. Lower the vehicle to the ground and torque lug nuts to 75-80 ft-lbs in a star pattern.

Reassembly

1. Ensure new cotter pin is properly installed and bent to prevent castle nut loosening
2. Verify brake caliper is securely mounted and brake hose is not twisted or strained
3. Check that all suspension components move freely without binding
4. Pump brake pedal several times to ensure proper brake feel before driving

Verification

• Perform visual inspection of ball joint installation to ensure it is fully seated and castle nut is properly torqued with cotter pin installed
• Grasp tire at top and bottom and attempt to rock it - there should be no vertical play indicating loose ball joint
• Test drive vehicle at low speed and verify no clicking, popping, or clunking noises from suspension
• Have front end alignment checked and adjusted by a qualified shop as suspension geometry has been disturbed

More procedures for this vehicle