This is a general overview; specific steps may vary slightly. Always consult a repair manual specific to your 2003 Pontiac Sunfire for detailed instructions and torque specifications. Failing to follow these specifications can lead to damage or injury.
Tools you'll likely need:
* Jack and jack stands: Absolutely crucial for safety. Never work under a car supported only by a jack.
* Wheel chocks: To secure the vehicle.
* Lug wrench: To remove the wheel.
* Socket set and wrench set (metric): Various sizes will be needed.
* Hammer and punch: For removing and installing components.
* Torque wrench: Essential for tightening components to the correct specifications.
* Bearing packing grease: Specific grease for wheel bearings.
* New front wheel bearings: Get the correct part number for your vehicle.
* Pry bar: May be needed to separate components.
* Penetrating oil (like PB Blaster): To help loosen rusted or seized parts.
* C-clamp or similar: Possibly needed to compress the bearing race.
* A suitable press or bearing separator: Ideally needed for proper bearing removal and installation, but some may be able to do it with careful use of a hammer and drift.
General Steps (Consult your repair manual for specifics):
1. Safety First: Park on a level surface, engage the parking brake, and use wheel chocks.
2. Remove the Wheel: Loosen the lug nuts before jacking up the car. Jack up the vehicle and securely place it on jack stands. Remove the wheel.
3. Remove the Brake Caliper: Remove the brake caliper and hang it securely out of the way using a bungee cord or wire. Be careful not to damage the brake line.
4. Remove the Rotor: Remove the rotor (brake disc). Sometimes this may require some persuasion with a hammer and punch (carefully).
5. Remove the Axle Nut: This is usually very tight. Use a breaker bar if necessary. Mark the nut's position relative to the hub before removal if your axle has a spline, so you can reassemble it in the same alignment.
6. Remove the Hub Assembly: This is often the most challenging step. It may require separating the hub from the spindle using a puller. The hub is likely pressed onto the bearing.
7. Remove the Old Wheel Bearings: This is where a press or bearing separator is ideal. Using a hammer and punch is possible but risky, and could damage the new bearings. The bearings are usually pressed into the hub assembly. You'll need to carefully remove the inner and outer races.
8. Clean and Inspect: Clean the hub assembly thoroughly. Inspect the spindle and other components for damage.
9. Install the New Wheel Bearings: Use a press if possible. This is crucial for avoiding damage to the new bearings. Pack the new bearings with the correct grease.
10. Reassemble: Reassemble the hub assembly, rotor, caliper, and wheel, tightening everything to the correct torque specifications found in your repair manual. This includes the axle nut.
11. Lower the Vehicle: Carefully lower the vehicle from the jack stands.
12. Test Drive: Test drive the vehicle to check for any issues. Listen carefully for any unusual noises from the wheel.
Important Considerations:
* Torque Specifications: Using the correct torque specifications is essential to prevent damage and ensure safety. Incorrect torque can lead to bearing failure or other problems.
* Repair Manual: A repair manual specific to your 2003 Pontiac Sunfire is indispensable. It will provide detailed instructions, diagrams, and torque specifications.
* Professional Help: If you are not comfortable with this repair, take your vehicle to a qualified mechanic. This is a job that can easily result in damage if not done correctly.
This information is for general guidance only. Always refer to a factory service manual for your specific vehicle before attempting any repairs. Improper repair can lead to serious injury or damage to your vehicle.
