This article provides practical advice for diagnosing and replacing a wheel bearing on a 2008 Chevy Impala. We’ll cover common symptoms, step-by-step replacement instructions, and some less-obvious tips gained from years of working on these cars. This article solves 3 problems: accurately diagnosing a bad wheel bearing, confidently replacing it yourself (saving money), and preventing future issues.
The first step is accurately identifying that your ’08 Impala’s wheel bearing is indeed the problem. Wheel bearings are crucial for smooth, quiet operation, and a failing one can lead to significant issues. Before you start tearing things apart, rule out other potential culprits like tires, brakes, or suspension components.
Common Symptoms
Here’s what to listen and feel for:
-
Growling or Humming Noise: This is the most common symptom. The noise usually increases with speed and may change in intensity when turning. It might sound like tire noise, but it’s more consistent and doesn’t typically vary with road surface changes like tire noise does.
-
Wobbling or Vibration: A severely damaged wheel bearing can cause noticeable vibration, especially at higher speeds. You might feel it in the steering wheel or the seat.
-
Play in the Wheel: Jack up the car and try to wiggle the wheel back and forth. Excessive play (more than a slight movement) indicates a problem with the bearing or potentially other suspension components. Always compare the amount of play to the other side of the car for comparison.
-
ABS Light: In some cases, a faulty wheel bearing can damage the ABS sensor, triggering the ABS light. However, this is less common.
-
Uneven Tire Wear: Although this is less direct, a failing wheel bearing can contribute to uneven tire wear over time.
Pinpointing the Location
Once you suspect a wheel bearing, figuring out which one is the issue is crucial.
- The “Load” Test: While driving at a speed where you hear the noise, gently swerve left and right. The noise will typically increase when the weight of the car shifts onto the bad bearing. For example, if the noise gets louder when you turn left, the right wheel bearing is likely the culprit. This method works because turning shifts the weight of the vehicle, stressing the bearing and exacerbating the noise.
- The “Spin” Test: With the car safely supported on jack stands, spin each wheel by hand. Listen carefully for any grinding, clicking, or roughness. If you hear something abnormal compared to the other wheels, that’s a strong indicator of a bad bearing. This test is best performed with someone else listening closely while you spin the wheel.
- Heat Check: After a drive, carefully (don’t burn yourself!) touch the wheel hub of each wheel. A failing bearing will often generate excessive heat compared to the others. Use caution! Brake heat can also skew this test, so try to avoid heavy braking before performing it.
Replacing a wheel bearing on an ’08 Impala is a moderately challenging DIY project. It requires some mechanical skill, proper tools, and a safe working environment. Always prioritize safety!
Tools You’ll Need
- Jack and Jack Stands
- Wheel Chocks
- Socket Set (including sizes for the axle nut, caliper bolts, and hub assembly bolts)
- Breaker Bar (for the axle nut)
- Torque Wrench
- Hammer
- Punch or Chisel
- Wheel Bearing Hub Assembly (specific to your ’08 Impala)
- Penetrating Oil (like PB Blaster)
- Brake Cleaner
- Gloves and Safety Glasses
- Optional: Slide Hammer with Hub Puller Attachment
Step-by-Step Instructions
-
Safety First: Park the car on a level surface, engage the parking brake, and chock the rear wheels. Loosen the lug nuts on the wheel of the bearing you’re replacing before lifting the car.
-
Lift and Secure: Jack up the car and securely support it with jack stands. Remove the wheel.
-
Brake Caliper Removal: Remove the brake caliper bolts (usually 13mm or 15mm). Carefully slide the caliper off the rotor. Do not let the caliper hang by the brake hose! Secure it to the suspension with a bungee cord or wire.
-
Brake Rotor Removal: The rotor may slide off easily. If it’s stuck, try tapping it gently with a hammer, or use penetrating oil. There are usually threaded holes in the rotor hat that you can thread bolts into to help push the rotor off the hub.
-
ABS Sensor Removal (If Applicable): Disconnect the ABS sensor wiring harness and carefully remove the sensor from the hub assembly. Be gentle; these sensors can be fragile. Spray with penetrating oil if necessary.
-
Axle Nut Removal: This is often the trickiest part. The axle nut is typically very tight. Use a breaker bar and the correct size socket to loosen it. You may need to have someone hold the brakes while you apply force. Penetrating oil is your friend here! Applying heat can also help loosen a stubborn nut, but be extremely careful and avoid damaging other components.
-
Hub Assembly Bolt Removal: Locate the bolts that secure the hub assembly to the steering knuckle (usually on the backside). Remove these bolts.
-
Hub Assembly Removal: The hub assembly is likely rusted in place. This is where a slide hammer with a hub puller attachment comes in handy. If you don’t have one, you can try using a hammer and punch to carefully drive the hub out from the backside. Work your way around the hub, applying even pressure. Be patient and persistent.
-
Cleaning: Once the old hub assembly is removed, clean the mating surfaces on the steering knuckle with a wire brush.
-
Installation: Install the new hub assembly, making sure it seats properly. Torque the hub assembly bolts to the manufacturer’s specifications.
-
Reassembly: Reinstall the ABS sensor (if applicable), brake rotor, brake caliper, and wheel.
-
Axle Nut Tightening: Tighten the axle nut to the manufacturer’s specified torque. This is critical for proper bearing preload. Consult a repair manual or online resource for the correct torque specification for your ’08 Impala.
-
Final Check: Lower the car and double-check all bolts and connections. Take the car for a test drive and listen for any unusual noises.
Having replaced numerous wheel bearings on ’08 Impalas, here are some insights I’ve gained:
The Axle Nut Struggle is Real
The axle nut on these cars is notorious for being difficult to remove. I’ve found that using an impact wrench in combination with heat is often the most effective approach. However, always exercise extreme caution when using heat near flammable materials like brake lines. A penetrating oil soak overnight can also make a significant difference.
Aftermarket vs. OEM
While aftermarket wheel bearing hub assemblies are often cheaper, I’ve had better luck with OEM (Original Equipment Manufacturer) parts in terms of longevity. The slightly higher cost is usually worth it in the long run. I’ve seen aftermarket bearings fail much sooner than their OEM counterparts.
Don’t Skimp on the Torque
Properly torquing the axle nut and hub assembly bolts is absolutely crucial. Under-torquing can lead to premature bearing failure, while over-torquing can damage the bearing or other components. Always use a torque wrench and follow the manufacturer’s specifications.
The Rust Factor
In regions with road salt, rust can be a major problem. I’ve encountered situations where the hub assembly was so corroded that it was nearly impossible to remove without damaging the steering knuckle. In these cases, I’ve had to resort to using a cutting torch to carefully cut the hub assembly into pieces to remove it. This is a last resort and should only be attempted by experienced mechanics.
Replacing the wheel bearing is only half the battle. Here’s how to help ensure it lasts:
Proper Installation
As mentioned above, proper torque is paramount. Double-check all torque specifications and use a quality torque wrench.
Wheel Alignment
After replacing a wheel bearing, it’s a good idea to have the wheel alignment checked. A misaligned wheel can put excessive stress on the bearing, leading to premature failure.
Avoid Potholes and Impacts
Hitting potholes and other road hazards can damage wheel bearings. Avoid them whenever possible.
Regular Inspection
Periodically inspect your wheel bearings for any signs of wear or damage. Catching a problem early can prevent more serious issues down the road.
| Issue | Possible Cause | Solution |
|---|---|---|
| Excessive Noise | Worn or damaged wheel bearing | Replace the wheel bearing |
| Vibration at High Speeds | Worn or damaged wheel bearing, unbalanced tires | Replace the wheel bearing, balance tires |
| ABS Light On | Damaged ABS sensor due to faulty bearing | Replace the wheel bearing and ABS sensor |
| Uneven Tire Wear | Worn or damaged wheel bearing, Misalignment | Replace the wheel bearing, perform wheel alignment |
| Difficulty Removing Hub | Corrosion | Apply penetrating oil, use a slide hammer, apply heat cautiously |
My expertise comes from over 15 years of experience as a mechanic, specializing in General Motors vehicles. I’ve performed countless wheel bearing replacements on various models, including the ’08 Chevy Impala.
While I’ve based much of this article on my practical experience, I’ve also consulted reputable sources to ensure accuracy. For general information on wheel bearings, Wikipedia is a good starting point: https://en.wikipedia.org/wiki/Wheel_bearing. (Please note that while Wikipedia provides background information, always consult a repair manual specific to your vehicle for torque specifications and detailed procedures.)
Furthermore, always refer to the specific service manual for your ’08 Chevy Impala. These manuals contain detailed diagrams and torque specifications that are essential for proper repair. These manuals can often be found online or purchased from automotive parts suppliers.
Welcome to our hub for all things bearings! Whether you're an engineer, a student, or simply curious, we provide in-depth knowledge, the latest news, and insightful articles covering a wide range of bearing types, applications, and industry trends. Explore our resources to enhance your understanding and stay informed about the world of bearings.
