However, if you're determined to do it yourself, here's a general outline. This is not a complete, step-by-step guide and may not cover all specifics for your particular vehicle. Always consult a repair manual specific to your 1990 Mercury Topaz for detailed instructions, torque specifications, and diagrams. A Haynes or Chilton manual would be a good investment.
Tools you'll likely need:
* Jack and jack stands: Crucial for safety. Never work under a car supported only by a jack.
* Lug wrench: To remove the wheel.
* Wheel chocks: To prevent the car from rolling.
* Socket set and wrenches: Various sizes will be needed.
* Hammer and punch: Possibly for stubborn parts.
* Pry bar: Might be helpful for separating components.
* Torque wrench: Essential for tightening bolts to the correct specification.
* Penetrating oil (like PB Blaster): To loosen rusted or seized bolts.
* New wheel bearing: Get the correct part number for your Topaz.
* Grease: Pack the new bearing with the appropriate grease.
* Wheel bearing press (optional but highly recommended): Makes the bearing installation much easier and safer. Improper installation can damage the bearing.
General Steps (Consult your repair manual for specifics):
1. Safety First: Park on a level surface, engage the parking brake, and use wheel chocks on the rear wheels.
2. Raise and Secure: Jack up the front of the car and securely place it on jack stands.
3. Remove the Wheel: Remove the lug nuts and take off the wheel.
4. Remove the Brake Caliper: Disconnect the brake caliper and secure it out of the way. You may need to support it with a wire or bungee cord. Be careful not to kink or damage the brake line.
5. Remove the Rotor: Remove the brake rotor (disc). This may require some persuasion.
6. Remove the Axle Nut: This is usually a large nut on the end of the axle. You'll likely need a breaker bar or impact wrench. Note its position and how many threads are showing.
7. Remove the Spindle Nut: Sometimes this is the same as the axle nut.
8. Separate the Hub Assembly: This is where it gets tricky. The hub assembly (containing the bearing) is usually pressed onto the spindle. You might need to use a puller or a hammer and punch (carefully!) to separate them.
9. Remove the Old Bearing: This will often require a wheel bearing press to avoid damage. If you're not using a press, proceed with extreme caution.
10. Install the New Bearing: Again, a press is highly recommended. Pack the new bearing with grease.
11. Reassemble: Reassemble everything in reverse order, making sure all components are correctly aligned. Pay close attention to the correct order and orientation of the parts.
12. Torque Specifications: Use your torque wrench to tighten all bolts to the manufacturer's specifications (found in your repair manual).
13. Lower the Car: Carefully lower the car and check your work.
14. Test Drive: Take a short test drive to check for any vibrations or unusual noises.
This is a simplified overview. The actual process will be much more involved and require specialized tools and knowledge. Improperly installing a wheel bearing can lead to serious accidents. If you're unsure about any step, do not proceed. Seek professional help from a qualified mechanic. The cost of a repair will be far less than the potential cost of an accident.
