ACDELCO 51814SK

• Use an Axle Nut Socket to remove the axle nut
• After removing the brake caliper, suspend it using a Caliper Hanger to avoid damage to the brake hose
• A Wheel Hub Removal Tool can help remove a stubborn wheel hub assembly from the knuckle
• During installation, use a Torque Wrench to tighten the axle nut to the manufacturer's specification. Do not use an impact wrench as it is easy to over tighten the axle nut. The torque specification can be found in your owner's manual

Wheel hub units are low maintenance parts, but that doesn’t mean they last forever. Uneven road surfaces, heavy driving conditions (such as towing or racing), and under-inflated tires put extra strain on the hub bearing and can lead to premature failure. Common signs of a bad hub unit include:

• A humming, rumbling or growling noise that increases with acceleration
• A loud constant whining or grinding noise when the vehicle is in motion
• Excessive play in the steering wheel
• Steering wheel vibration that changes with the vehicle speed or as the vehicle turns
• ABS system malfunction

It is often difficult to pinpoint which hub unit has gone bad while driving because noise and vibration travels through the frame of the vehicle. Here are a two tests you can do to help identify which hub unit has gone bad:

Shake Test: Identifying Play or Looseness

1. Lift your vehicle so the wheel is off the ground
2. Place your hands on the sides of the tire and try to shake the wheel
3. Now place your hands on the top and bottom of the tire and try to shake the wheel again
4. If you feel movement in both directions, you have play in your bearing and it needs to be replaced
5. Note: If you feel movement when shaking the wheel left to right, but not top to bottom, you could have a worn out tie rod end. Similarly, if you have movement top to bottom, but not left to right, you may have a worn out ball joint.

1. Lift your vehicle so the wheel is off the ground and can spin freely
2. Spin the wheel, in either direction, and listen for a grinding or howling noise
3. If you hear a loud grinding or howling noise, that increases with the speed of the wheel, you have a failed bearing that needs to be replaced
4. Note: It is best to test both front or both rear bearings at the same time so you can compare the difference between the two sides. If you have a failed bearing, there will be a noticeable difference in the amount of noise you hear during this test

ACDelco breaks down their premium portfolio of Original Equipment and Aftermarket parts into two tiers: GM Original Equipment and ACDelco Gold.