How to Replace a Front Wheel Bearing

Introduction

This tutorial will guide you through the process of replacing the front wheel bearing hub assembly on a 2007 Mercury Mountaineer, although the steps are applicable to many vehicles with a similar setup. Performing this task yourself can save you a significant amount of money compared to dealership costs.

Step 1: Diagnose the Wheel Bearing

• Listen for unusual sounds like rumbling, which can indicate a bad wheel bearing.
• Check for warning lights on the dashboard, such as ABS and traction control lights.
• Use an OBD2 scanner to read codes related to the wheel bearing, such as C1233 or C1155.

Step 2: Prepare the Vehicle

• Safely jack up the vehicle and support it on jack stands, ensuring the rear tires are blocked.
• If needed, remove the wheel to access the axle nut.

Step 3: Remove the Axle Nut

• Use a 32 mm axle nut socket and a breaker bar to loosen the axle nut. If it's too tight, consider using a cheater bar for extra leverage.
• Once loosened, remove the axle nut completely.

Step 4: Remove the Brake Caliper and Rotor

• Use a 21 mm socket to remove the two caliper bracket bolts.
• Support the brake caliper with a bucket to avoid damaging the brake line.
• Hit the axle stud inward gently with a hammer while the axle nut is slightly threaded on to break it free.

Step 5: Remove the Wheel Bearing Hub Assembly

• Locate the three bolts securing the bearing hub assembly. They are typically 15 mm bolts.
• Use a breaker bar to crack these bolts loose, then remove them completely with a ratchet.
• Before pulling off the hub assembly, disconnect the ABS sensor.

Step 6: Use a Slide Hammer for Stubborn Hubs

• If the hub assembly is stuck, use a slide hammer. Attach it to the hub using lug nuts and yank it multiple times to detach it.
• If necessary, apply penetrating fluid at the seam where the hub meets the knuckle.

Step 7: Clean and Prepare the Mounting Surface

• Clean the mounting surface with sandpaper or an abrasive sponge to remove rust and debris.
• Apply anti-seize compound on the threads and the surface to prevent future binding.

Step 8: Install the New Wheel Bearing Hub Assembly

• Align the new hub bearing with the spindle, ensuring the ABS wire is positioned correctly.
• Hand-tighten the three bolts, then apply blue Loctite to prevent loosening from vibrations.

Step 9: Torque the Bolts

• Use a torque wrench to tighten the three hub bolts to 75 ft-lbs.
• Reconnect the ABS wire, ensuring it is securely fastened.

Step 10: Reassemble the Brakes

• Reinstall the brake caliper and tighten the caliper bolts with blue Loctite.
• Torque the caliper bolts to 100 ft-lbs.

Step 11: Final Assembly

• Place the wheel back on and snug down the lug nuts.
• Lower the vehicle and torque the lug nuts to 100 ft-lbs.
• Install the new axle nut and torque it down to 190 ft-lbs.

Conclusion

Replacing a front wheel bearing can be a straightforward process with the right tools and techniques. Follow these steps carefully, and you'll ensure a successful installation. After completing the job, take the vehicle for a test drive to confirm that the issue is resolved and that the ABS and traction control lights are off. If you found this guide helpful, consider checking out other related tutorials on wheel bearing replacements.