2019-2025 Tesla Model S & Model X Drive Axle: Diagnosing Shudder, Clicks, and Vibrations

Symptoms of a Failing Drive Axle Shaft

Drive axle failure in the 2021-2025 Tesla Model S and 2019-2025 Tesla Model X often manifests as distinct noises and vibrations, particularly during acceleration. Because these vehicles are so quiet, drivetrain noises are often more noticeable than in a gasoline-powered car.

1. Shudder or Vibration During Acceleration

This is the most widely reported symptom for these models. You will feel a noticeable shudder, shake, or vibration from the front of the vehicle, especially during hard acceleration. This issue has been persistent enough that Tesla has issued Technical Service Bulletins (TSBs) for it. The vibration is caused by premature wear within the inner CV joints, which can develop imperfections or pitting due to the high torque and the specific angle of the axles. The problem can sometimes be more pronounced when the vehicle's air suspension is set to a higher ride height.

2. Clicking or Popping Noises When Turning

A classic sign of a worn outer CV joint is a rhythmic clicking or popping sound that occurs when making sharp turns at lower speeds. This noise happens because the bearings inside the worn joint have too much space and click against each other as they rotate. This symptom is common to all vehicles with CV axles, including Teslas.

3. Clunking Noise on Acceleration or Deceleration

A "clunk" or "thump" when you start to accelerate or shift between drive and reverse can indicate excessive play in a worn inner CV joint. This sound is the result of the joint's internal components slamming together as the torque is applied or reversed. Some owners also report a clicking noise that can be resolved by lubricating the axle splines where they enter the wheel hub.

Known Issues, TSBs, and Recalls

The primary known issue for these drive axles is the "acceleration shudder." This has been a recurring problem for Model S and Model X vehicles for many years, stemming from the high stress placed on the front CV joints by the powerful electric motors. The design places the half-shafts at a steep angle, which accelerates wear on the internal components of the CV joints.

• Technical Service Bulletin SB-21-39-001: This bulletin specifically addresses customer complaints of "excessive vibrations from the front drive unit during hard acceleration." The prescribed fix is to replace both front drive unit half-shafts with updated components and, in some cases, replace the front drive unit clevis and axle seal. The bulletin notes that this is a Noise, Vibration, and Harshness (NVH) issue and does not affect steering, braking, or safety.
🎬 Watch: Does this Tesla service bulletin actually fix the vibration?

As of early 2026, there are no specific NHTSA recalls for the drive axle shafts themselves on these models. Recalls for these vehicles have focused on other areas like airbags, software, and suspension fasteners.

Buying a Used Drive Axle Shaft

A used OEM drive axle is often a cost-effective and reliable alternative to expensive new parts, especially when cheap aftermarket options may not be built to handle Tesla's torque. Here’s what to look for:

1. Physical Inspection

• Inspect the CV Boots: The rubber boots at each end of the axle are the most critical inspection point. They should be free of any rips, tears, or cracks. A torn boot allows the lubricating grease to escape and contaminants like dirt and water to enter, which quickly destroys the CV joint. If you see grease splattered on the inside of the wheel or under the car, it's a sure sign of a failed boot.
• Check for Play: Hold the shaft and try to move the joints. There should be very little in-and-out (plunge) movement and almost no rotational slop. Excessive play indicates a worn joint.
• Look for Damage: Inspect the shaft itself for any signs of bending, heavy corrosion, or damage from impact. Check the splines on both ends to ensure they are not stripped or damaged.

2. Compatibility and Part Numbers

Always match the part number from your original axle to the used part you are buying. Some known OEM part numbers include: 1027113-00-B, 1027161-00-C, 1420113-00-B, 1420119-00-B, 1626636-00-A, and 1626638-00-A. This is not an exhaustive list, and part numbers are frequently superseded. The only way to be certain is to check your specific vehicle's original part.

3. Mileage Considerations

While there is no specific mileage at which these axles fail, the shudder issue can appear at relatively low miles for some owners. When buying used, look for an axle from a lower-mileage vehicle if possible. However, the condition of the CV boots is a more important indicator of lifespan than mileage alone. A high-mileage axle with intact boots is likely in better condition than a low-mileage one with a torn boot.

Cost Breakdown

Replacing a drive axle on a Model S or Model X can be expensive, especially at the dealership. A used OEM part can offer significant savings.

Replacement Procedure Overview & Torque Specs

Replacing the drive axle is a moderately difficult job that can be performed by an experienced DIY mechanic. It involves removing the wheel, brake caliper, and various suspension links to gain access to the axle.

Key Steps:

1. Engage Jack Mode: Before lifting, you must put the vehicle's air suspension into 'Jack Mode' via the touchscreen to prevent it from self-leveling.
2. Remove Axle Nut: The large central axle nut must be removed. 🎬 Watch this quick guide to fixing the common axle click. This is a 32mm nut and is torqued very tightly.
3. Disconnect Suspension: Several suspension links (like the upper link and toe link) must be disconnected from the wheel knuckle to allow the knuckle to swing out of the way.
4. Separate Axle from Hub: The axle splines can be tight in the wheel hub. A hub puller may be needed to push the axle out.
5. Remove Axle from Drive Unit: The inner end of the axle pops out of the drive unit. A pry bar or a special tool may be needed to release the retaining clip.
6. Installation: When installing the new axle, be careful not to damage the drive unit's oil seal. Always use a new axle nut, as it is a one-time-use, torque-to-yield component.

Critical Torque Specs:

• Rear Axle Nut: 245 Nm (180.7 lb-ft). Some sources may list up to 300 Nm (221.2 lb-ft); always verify the correct spec for your specific model and year.
• Front Axle Nut (Model X): One DIY source mentions 180 ft-lbs, but it's best to confirm with an official service manual.
• Brake Caliper Bolts: ~120-125 Nm (92.2 lb-ft).
• Suspension Link Bolts: Range from 130 Nm to 150 Nm (96 to 110 lb-ft) depending on the specific link.

Frequently Asked Questions