2016-2025 Tesla Model S & Model X Steering Knuckle: Noises, Part Numbers, and the Critical 2021 Refresh

Symptoms of a Failing Steering Knuckle Assembly

On the Tesla Model S and Model X, the steering knuckle is the main structural component, but the part that most commonly fails is the separate, bolt-on wheel hub and bearing assembly. Because they work together, symptoms can be related to either part.

• Humming, Whirring, or Grinding Noises: This is the most common sign of a bad wheel bearing inside the hub assembly. The noise is often described as a hum or a growl that starts at a certain speed (e.g., above 40 mph) and gets louder as speed increases. The sound may also change pitch or intensity when turning, as weight shifts from one side of the car to the other.
• Clunking or Knocking Over Bumps: A clunking or knocking sound, especially at low speeds over bumps or when turning into a driveway, often points to wear in the ball joints of the control arms that attach to the knuckle. While not a failure of the knuckle itself, it's a very common source of noise in the front suspension assembly.
🎬 See how to diagnose and fix suspension rattles
• Vehicle Pulling to One Side: If the knuckle itself is bent from hitting a curb or a severe pothole, it can throw the wheel alignment out of specification. This will cause the vehicle to persistently pull to the left or right, requiring constant steering correction.
• Uneven or Rapid Tire Wear: A bent knuckle directly impacts alignment angles like camber and toe. This forces the tire to make improper contact with the road, leading to accelerated wear on the inner or outer edges.
• Loose or Vibrating Steering Wheel: Excessive play in a worn wheel bearing or damage to the knuckle can translate into a feeling of looseness or vibration in the steering wheel.

Known Issues, Recalls, and Service Bulletins

While there are no major recalls specifically for the steering knuckle itself, several related issues and investigations are important for owners of the 2016-2025 Tesla Model S and Model X to be aware of.

• NHTSA Investigation PE20-014 (Front Suspension Fore Links): The National Highway Traffic Safety Administration (NHTSA) investigated failures of the front suspension fore links on 2015-2017 Model S and 2016-2017 Model X vehicles. The investigation found hundreds of failures, mostly occurring at low speeds. While it was closed without a formal recall, Tesla had previously issued a service bulletin (SB-17-31-001) to address the issue on some vehicles. A failed link can affect wheel position and control.
🎬 Watch: How to fix squeaky Tesla suspension issues
• NHTSA Campaign 22V818000 (Loss of Power Steering): This recall affected certain 2017–2021 Model S and Model X vehicles. A software issue could cause a loss of power steering assist after driving over rough roads or hitting a pothole. Tesla addressed this with an over-the-air (OTA) software update.
• Corroded Steering Rack Bolts: Earlier models (pre-April 2016 Model S and pre-October 2016 Model X) were recalled for aluminum steering gear bolts that could corrode and break, leading to a loss of power steering. The fix involved replacing the aluminum bolts with steel ones.

Crucial Compatibility Guide: Pre-Refresh vs. 2021+ Palladium/Plaid

Pre-Refresh Models (approx. 2016 - early 2021)

These vehicles use a distinct knuckle design. Part numbers for this era typically begin with a prefix like 102xxxx or 600xxxx. Always confirm the part number on your original part before ordering.

• Common Part Numbers: 1027311-00-F (Front Left), 1027316-00-D/F (Front Right), 6007018-00-C (Front Right, earlier models).
• Identification: These knuckles connect to a different set of control arms compared to the later models. Visual comparison is essential.

Refresh 'Palladium' & Plaid Models (approx. mid-2021 - 2025)

The refreshed models feature an updated suspension architecture, requiring a completely different knuckle. Part numbers for this generation typically start with a prefix like 14xxxxx or 16xxxxx.

• Common Part Numbers: Part numbers in this series often denote front/rear and left/right for the newer design.
• Plaid vs. Non-Plaid: There are specific knuckles for Plaid performance models, likely to accommodate different braking or suspension loads. For example, part numbers 1420311-00-F and 1420416-00-G have been identified on Plaid models. It is critical to verify the correct part for your specific trim.

Buying a Used Steering Knuckle: What to Inspect

A used OEM steering knuckle is an excellent value, as the knuckle itself is a robust piece of cast aluminum unlikely to fail without a major impact. However, the included wheel hub/bearing assembly is a wear item. Here’s what to check:

1. Verify the Part Number: This is the most critical step. Due to the 2021 refresh, Plaid/non-Plaid differences, and S/X variations, the part number stamped on the knuckle must match your original part.
2. Inspect for Cracks or Bends: Carefully examine the entire knuckle, especially around the mounting points for the control arms and brake caliper. Any sign of cracking, bending, or significant impact damage means the part is unsafe and should be rejected.
3. Check the Included Hub/Bearing: If the used knuckle comes with a hub assembly, grab the hub flange and try to wiggle it. There should be absolutely zero play, roughness, or noise when you spin it. Given that the bearing is the most common failure point, consider its mileage. A low-mileage assembly is ideal. If the bearing feels worn, you will need to purchase a new hub/bearing assembly separately.
4. Examine Mounting Holes: Ensure the tapered holes for the ball joints and tie rod are clean and not distorted or enlarged. A worn mounting hole can prevent the joint from seating correctly, leading to persistent suspension noise.
5. OEM vs. Aftermarket: For a critical safety component like a knuckle, a used OEM part is often superior to a new, cheap aftermarket one. OEM parts are made to precise factory specifications for material strength and geometry, ensuring proper fit and function. Some aftermarket bearings have been reported to cause error messages with the vehicle's systems.

Replacement Overview and Torque Specs

Replacing a steering knuckle is an advanced DIY job (4/5 difficulty) that requires proper tools and safety procedures. A four-wheel alignment is mandatory after the job is complete to ensure safety and prevent tire wear.

Is Rebuilding an Option? No. The wheel hub and bearing is a sealed, non-serviceable unit with a factory-set preload. It cannot be pressed apart and rebuilt; the entire hub assembly must be replaced. The knuckle itself cannot be repaired if cracked or bent.

Cost Comparison

The cost to replace a steering knuckle assembly can vary significantly based on the parts needed and local labor rates.

Frequently Asked Questions (FAQ)