Tesla Model S, Model X suspension failures – US NHTSA recommends expanding service bulletin

Following a four-year investigation into suspension failures involving a number of Tesla vehicles, the National Highway Traffic Safety Administration (NHTSA) has recommended that the EV maker widens its service bulletin to cover any vehicle equipped with components bearing the faulty part numbers, reported Ars Technica.

Said to be known among the Tesla community as the ‘whompy wheel’ issue, hundreds of incidents of front suspension failures were found to have affected the Tesla Model S and Model X, according to the Office of Defects Investigation of the NHTSA.

Evaluation by the NHTSA began in November 2020 when 43 reports of left- or right-front suspension fore link failures were reported in the Model S of 2015 to 2017 model years, and the Model X of 2016 to 2017 model years. This came after a service bulletin from Tesla in 2017 for the replacement of front suspension fore links in some vehicles, if either the left or the right fore link was damaged, or if the vehicle was due for alignment.

While Tesla eventually issued a recall in China in 2017 following pressure from authorities in the country, the electric vehicle maker told regulators in the United States that the issue was due to driver abuse, according to a Reuters report.

Though the service bulletin was issued by Tesla in 2017, the NHTSA said that the subpopulation of vehicles affected by the bulletin which were built between January and May 2016 only constituted 25% of failures identified by the probe.

However, suspension failures sustain by Tesla vehicles had become more frequent by 2020, according to the North American transport agency. “Forty-one (41) of the incidents have occurred in the last 18 months, including nine of the incidents that occurred while driving and all four that occurred at highway speeds,” the NHTSA wrote to Tesla.

The agency was able to identify 426 reports of either a Model S or a Model X sustaining suspension failure due to a faulty suspension fore link, and it was able to narrow down the scope to a pair of part numbers, wrote Ars Technica.

Just one suspension failure resulted in a minor crash, while eight instances of part failure occurred above 40 mph (64 km/h), which did not result in loss of driver control, however the NHTSA concluded that “this does not constitute a finding by the agency that a safety-related defect is not present; the agency will take further action if warranted by additional information received.”

Looking to sell your car? Sell it with Carro.