NHTSA Ends Four-Year Investigation into Tesla Suspension Failures, Urges Expansion of Service Bulletin

TapTechNews August 15th news, the National Highway Traffic Safety Administration (NHTSA) Office of Defects Investigation has ended a four-year investigation into suspension failures in some Tesla vehicles. This issue has been known as the whompywheel problem among Tesla owners. The NHTSA investigation found hundreds of front suspension failure incidents involving Model S sedans and Model X SUVs.

Although Tesla had previously issued a service bulletin calling for the replacement of faulty parts on some vehicles, the NHTSA said that more vehicles are equipped with the faulty parts and the scope of vehicles covered by the service should be expanded.

TapTechNews noted that after receiving 43 reports of left and right front suspension tie rod failures in 2015 to 2017 Model S and 2016 to 2017 Model X electric vehicles, the NHTSA began a preliminary investigation in November 2020. Most of them occurred during low-speed parking, and only four occurred during high-speed driving.

Tesla issued a service bulletin in 2017 to replace the front suspension tie rods of some vehicles if the left and right tie rods were damaged or needed a four-wheel alignment. Although Tesla finally recalled some vehicles in China under the pressure of regulatory authorities, according to Reuters, the company told the US regulatory agency that the problem was caused by driver abuse.

But three years later, the NHTSA noticed that the Tesla suspension failure problem became more and more common. In a letter to the automaker in December 2020, the agency noted that among the 53 cases determined at that time, 41 accidents occurred in the past 18 months, of which 9 occurred during driving and 4 occurred on highways.

During the investigation, the NHTSA determined a total of 426 reports of Model S or Model X suspension failures due to front tie rod failures. More specifically, the investigation located the problem to two part numbers. Fortunately, only one suspension failure led to a crash (minor), and even in the 8 failures at speeds over 40 miles per hour (64 kilometers per hour), the vehicles did not lose control.

Although Tesla issued a service bulletin in 2017, the NHTSA said that the subgroup of vehicles covered by the bulletin (produced from January to May 2016) only accounted for 25% of the failures determined by the investigation.

Since the suspension failure does not cause the vehicle to lose control, the NHTSA decided to end the investigation and recommended that Tesla expand the scope of the service bulletin to cover any vehicles equipped with these two faulty front tie rod part numbers.