Here's a general procedure. Specifics might vary slightly depending on your exact model and any aftermarket modifications. Always consult a repair manual specific to your vehicle for detailed instructions and torque specifications. This is a general guideline only.
Tools You'll Likely Need:
* Jack and jack stands: Essential for safely lifting the vehicle.
* Wheel chocks: To secure the vehicle on the ground.
* Socket wrench set: Various sizes, likely including metric.
* Wrench set: For bolt access.
* Penetrating oil (PB Blaster, etc.): To loosen rusted or seized bolts.
* Torque wrench: To tighten bolts to the correct specification (crucial to prevent damage).
* Shop rags or towels: To keep things clean.
Procedure:
1. Safety First: Park on a level surface, engage the parking brake, and chock the front wheels. Lift the rear of the car using a jack and securely support it with jack stands. Never work under a car supported only by a jack.
2. Remove the Wheel: Remove the wheel from the side you're working on.
3. Locate Shock Mounts: Identify the top and bottom shock mounts. The top mount is usually bolted to the chassis, and the bottom mount is attached to the axle or control arm.
4. Disconnect the Shock Absorber:
* Top Mount: There will be bolts securing the top of the shock to the vehicle's body. Spray penetrating oil on these bolts and let it sit for a while to help loosen them. Use the appropriate sockets and wrenches to carefully remove these bolts.
* Bottom Mount: Similarly, locate and remove the bolts securing the bottom of the shock to the axle or control arm. Again, penetrating oil is your friend.
5. Remove the Shock Absorber: Once the top and bottom bolts are removed, carefully lower the shock absorber out of its mounting location. It might be somewhat stiff, so use caution.
6. Installation of New Shock Absorber: The installation process is the reverse of removal. Make sure to install the new shock absorber correctly. Lubricate the bushings (if necessary) before installing.
7. Tighten Bolts: Tighten all bolts to the manufacturer's specified torque using your torque wrench. Improper tightening can lead to premature wear or failure.
8. Reassembly: Replace the wheel, lower the vehicle, and check for proper function. Repeat steps for the other side.
Important Considerations:
* Rust and Corrosion: On older vehicles, bolts can be severely rusted or seized. Penetrating oil and patience are key. If a bolt breaks, you might need to drill it out and potentially replace it.
* Spring Tension: The springs are under considerable tension. Be extremely careful to avoid injury. If you're uncomfortable working with springs, consider having a professional perform the replacement.
* Repair Manual: Again, a repair manual specific to your 1998 Mercury Grand Marquis is invaluable. It will provide detailed diagrams, torque specifications, and step-by-step instructions.
This is a complex procedure. If you are not comfortable performing this repair yourself, it's strongly recommended to take your vehicle to a qualified mechanic. Improper installation can lead to dangerous driving conditions and damage to your vehicle.
