2003 - 2008 BMW Z4 Hub Assembly - Front (OEM)

What to Look for When Buying This Part

• Make sure the part is compatible with your vehicle's year, make, and model.
• Check the condition of the part (especially for used parts).
• Read reviews from other buyers.
• Consider the warranty offered by the seller.

Quality Indicators for the Available Options

What's Typically Included with the Part

• The hub assembly itself.
• Sometimes includes the wheel studs.
• May or may not include the ABS sensor.

Difficulty Level and Estimated Time

• Difficulty: Intermediate
• Estimated Time: 1-3 hours per side

Special Tools Needed (if any)

• Socket set
• Wrench set
• Torque wrench
• Hammer
• Wheel bearing removal tool (may be needed)
• Jack and jack stands

Critical Steps and Tips

1. Loosen the lug nuts before lifting the vehicle.
2. Securely support the vehicle with jack stands.
3. Disconnect the ABS sensor (if applicable).
4. Remove the brake caliper and rotor.
5. Remove the old hub assembly.
6. Install the new hub assembly, ensuring it is properly seated.
7. Torque all bolts to the manufacturer's specifications.
8. Reinstall the brake caliper and rotor.
9. Reconnect the ABS sensor (if applicable).

Whether DIY is Recommended or Professional Installation is Better

• DIY is possible for mechanically inclined individuals.
• Professional installation is recommended if you are not comfortable working on your car's brakes or suspension.

Compare: Used OEM, Refurbished OEM, New Aftermarket

• Choosing the right hub assembly depends on your budget and desired level of reliability. All the options below offer good value.

Used OEM

• Best value option.
• Genuine factory parts.
• Tested and inspected to ensure they are in good working condition.
• Significantly lower prices than new parts.

Refurbished OEM

• Factory parts that have been professionally restored.
• Worn components are replaced with new ones.
• Offers a balance of price and reliability.

New Aftermarket

• Brand new parts manufactured by third-party companies.
• Built to meet or exceed OE specifications.
• Can be a good option if you are looking for a new part at a competitive price.

Parts Commonly Replaced or Checked at the Same Time

• Wheel bearings
• ABS sensor
• Brake rotors
• Brake pads
• Ball joints
• Tie rod ends

Why Replacing Related Parts Prevents Repeat Failures

• Replacing worn related parts can prevent premature failure of the new hub assembly. For example, worn wheel bearings can put extra stress on the hub assembly, causing it to fail sooner. Replacing brake components at the same time ensures optimal braking performance.

How Long This Part Normally Lasts

• A hub assembly typically lasts between 75,000 and 150,000 miles.

Factors that Affect Longevity

• Driving conditions (e.g., rough roads, potholes).
• Maintenance habits (e.g., regular lubrication).
• Quality of the part.
• Driving style (e.g., aggressive driving).

Budget vs Mid-Range vs Premium Options

• Used OEM: $50 - $150
• Refurbished OEM: $100 - $250
• New Aftermarket: $150 - $350

Labor Cost Considerations if Applicable

• Labor costs for hub assembly replacement typically range from $150 to $400 per side, depending on the shop and location.

Total Job Cost Estimates

• DIY: $50 - $350 (depending on the part chosen)
• Professional Installation: $200 - $750 (including parts and labor)

Known Issues for This Vehicle's System Related to This Part

• Some models are prone to ABS sensor failure due to the sensor's proximity to the hub assembly.
• Check for any Technical Service Bulletins (TSBs) related to the hub assembly on your specific model year.

Any TSBs or Common Complaints

• It's always a good idea to check with your local dealer or online resources for any TSBs related to hub assembly issues on your specific BMW model.

How to Confirm Proper Operation

• Test drive the vehicle at various speeds.
• Listen for any unusual noises, such as grinding or humming.
• Check for vibrations in the steering wheel or floorboard.
• Make sure the ABS light is not on.

What to Look/Listen for to Verify It's Working Correctly

• Smooth and quiet operation.
• No vibrations or unusual noises.
• Proper ABS function (if applicable).
• No looseness or play in the wheel.

Q: How do I know if my wheel bearing is bad or my hub assembly?
A: A bad wheel bearing will often cause a humming or grinding noise that gets louder as you speed up. A bad hub assembly can cause similar noises, but you might also feel looseness in the wheel or hear clicking when turning. It's best to have a mechanic inspect it to be sure.

Q: Can I drive with a bad hub assembly?
A: It's not recommended. A failing hub assembly can cause the wheel to wobble, which can lead to loss of control and potentially an accident. It can also damage other components like the ABS sensor.

Q: How long does it take to replace a hub assembly?
A: It usually takes between 1 and 3 hours per side, depending on your experience and the tools you have available.

Q: What is the difference between a wheel hub and a wheel bearing?
A: The wheel bearing is a set of steel balls or rollers held together by a metal ring, and it allows the wheel to rotate smoothly. The hub is what the wheel bearing sits inside of, and it's what the wheel and brake rotor attach to. The hub assembly is the entire unit, including the hub, bearing, and sometimes the ABS sensor.

Q: Do I need to replace the ABS sensor when I replace the hub assembly?
A: Not always, but it's a good idea to inspect the ABS sensor when replacing the hub assembly. If the sensor is damaged or corroded, it should be replaced. Sometimes the hub assembly comes with a new ABS sensor.

OEM Part Numbers:

• BMW: 31211139345, 31211468926, 31221139345, 31221468926, 31222229501, 31226757024

Fits Years: 2003 2004 2005 2006 2007 2008