Here's a general outline. Specific steps may vary slightly depending on your van's exact configuration:
Tools You'll Likely Need:
* Jack and jack stands: Essential for safe vehicle support.
* Wheel chocks: To prevent the van from rolling.
* Lug wrench: To remove the wheel.
* Ball joint separator: This is crucial. A pickle fork is often used but risks damaging the control arm. A ball joint press is the best option if you have one.
* Hammer (if using a pickle fork): Use a mallet or rubber mallet if possible.
* Socket wrench set: You'll need sockets to remove the cotter pin and castle nut.
* Penetrating oil (PB Blaster or similar): Spray this generously on the ball joint several hours before starting. This greatly aids in separation.
* Torque wrench: For proper reinstallation.
* New lower ball joint: Replace the ball joint, don't just reuse the old one.
* Grease: Pack the new ball joint with grease.
* Wrench for the castle nut: The correct size will depend on your vehicle.
* Cotter pin pliers: For removing and installing the cotter pin.
Steps:
1. Safety First: Secure the vehicle with jack stands. Chock the wheels.
2. Remove the Wheel: Remove the lug nuts and take off the wheel.
3. Disconnect the Brake Caliper: This might be necessary to access the ball joint, depending on how much clearance you have. Use a suitable wrench to loosen and remove the caliper mounting bolts, and carefully hang the caliper out of the way using zip ties or wire. Do not let the brake line hang freely; support it to avoid damage.
4. Remove the Cotter Pin and Castle Nut: Locate the castle nut on the lower ball joint stud. Remove the cotter pin with the cotter pin pliers. Then, unscrew the castle nut using the appropriate socket and wrench.
5. Separate the Ball Joint: This is the trickiest part. Using a ball joint separator is highly recommended. A pickle fork can damage the control arm. Apply penetrating oil generously and carefully work the separator between the ball joint and the control arm. Use firm but controlled pressure. If using a ball joint press, it will make this step much easier.
6. Remove the Ball Joint: Once separated, the ball joint should come out relatively easily.
7. Installation of New Ball Joint: Reverse the process for installation. Ensure the new ball joint is properly seated and greased. Tighten the castle nut to the manufacturer's specified torque (check your repair manual). Install the cotter pin.
8. Reconnect the Brake Caliper: Carefully reattach the brake caliper and ensure it's properly secured.
9. Reinstall the Wheel: Put the wheel back on and tighten the lug nuts.
10. Lower the Vehicle: Slowly lower the vehicle to the ground.
11. Torque Spec Check: Double-check the torque specifications for the castle nut and lug nuts in a repair manual specific to your vehicle.
Important Considerations:
* Repair Manual: A repair manual specific to your 1994 Ford Aerostar is invaluable. It will provide detailed diagrams, torque specifications, and other crucial information.
* Parts: Ensure you get the correct replacement lower ball joint for your vehicle.
* Professional Help: If you're not comfortable performing this repair yourself, take your van to a qualified mechanic. Ball joints are critical safety components.
This is a general guide. Always consult a repair manual for your specific vehicle before attempting this repair. Incorrect installation can lead to serious safety hazards.
