Tesla Motors is working double-time to resolve defective drive units in 1,100 Norwegian Model S sedans in this, one of its most important markets.

EVs now enjoy 15 percent market share in the country of around 5.4 million people; the longer range, nicer Model S sales volume has surpassed the Nissan Leaf, but the units are experiencing premature failure.

Instead of the smooth sound of electric propulsion, Norwegian owners have reported noises like a circular saw operating and a “clunk” sound. Not good.

Tesla CEO Elon Musk has made it a priority, and according to Norway Today, Tesla is flying 300 new motor units per week from California. It is also hiring more techs to do the repairs, and projects the problem will be dealt with in a month or so.

While the U.S. market also experienced drive unit failures, Musk explained where issue arose:

“Unfortunately, this happened when a large batch of cars were produced for Norway, affecting approximately 1,100 vehicles,” said Musk as reported by NASDAQ. “Approximately 1% have experienced premature wear out of the coupling.”

Putting a finer point on it, Norway Today cited a newspaper report that said the electric motor to “provider box” connection lacked enough grease, and the drive shaft teeth are being destroyed.

SEE ALSO: Tesla Updates Warranty Mileage to Infinity

This report adds to other teething problems the company has experienced with its high-end electric sedan. Edmunds and Consumer Reports both reported issues, and individual Model S owners have also not been without problems here and there.

Overall, the Model S is being highly praised by owners, and Tesla’s rapid response and desire to make warranty repairs as pain-free as possible has helped much.