BMW will soon begin a safety recall of certain 2020 and 2021 xDrive models for faulty parts. They could break because of an error during production. 

Which parts are faulty and why? And if you’re one of the few affected by this BMW recall, how will your vehicle be repaired?

The parts involved in this BMW recall

Early last month, BMW submitted a recall report to the National Highway Traffic Safety Administration (NHTSA) for 2020 and 2021 BMW 530i xDrive, 540i xDrive, and 2021 740Li xDrive models. The issue involves the left and right output shafts, which transfer power to the rear wheels from the driveshaft.

The issue surfaced in October 2020 when BMW received a field report from outside the United States about a 2020 BMW 5 Series model that had a powertrain problem involving a rear output shaft. The automaker requested the part, and by the end of that month, BMW began to study it.

In November, the study showed the shaft’s surface hardness and curing depth didn’t meet specifications. BMW believed an improper heat treatment during manufacturing caused the problem. For the remainder of 2020, the automaker continued evaluation and even tried to replicate the supplier’s process showing the flaw.

By January 2021, after further study and a review of the supplier’s production records, BMW determined the flaw had happened during production at the supplier. According to the safety recall report that BMW filed with the NHTSA, a sensor that monitored the heat treatment process during the faulty shafts’ production was damaged. It might have failed to work properly and left room for error.

The automaker determined that only a small number of vehicles produced between March and July 2020 were affected. In late January 2021, BMW elected to do a voluntary recall to address the situation proactively. 

Because the shafts don’t meet specifications, owners of the affected xDrive vehicles could experience a loss of drive power and an increased risk of accidents. These vehicles could also roll away if parked without the parking brake. 

What is BMW xDrive?

All-wheel drive has been around for more than a century. BMW joined late in the game with the 1985 E30 325iX, BMWBlog reports. The German automaker’s first AWD SUV arrived in 1999 with the X5. Its all-wheel-drive indicator was right up front.

BMW’s xDrive is the all-wheel-drive system the brand has used on various models since 2003. There are many variations, but the xDrive approach to AWD uses electronic control, BMWBlog explains. 

The Dynamic Stability Control (DSC) program uses wheel speed sensors to detect any wheel slip and compensate for the steering angle. If the wheel slip amount is enough for the DSC to pick up, the clutch pack is activated and sends torque to the axle in the best position to put power on the road. 

The system can also apply additional braking force to a slipping wheel on the axle with the most power to optimize the available grip.

What you need to know about the recall

BMW plans to notify the affected owners on March 29. Last month, the automaker alerted dealers, who will replace the faulty output shafts free of charge. According to the recall reported submitted to the NHTSA, only 28 vehicles are affected.

If you’re an owner of one of the affected models, expect to get a notice on March 29. You may also contact BMW customer service at 800-525-7417, the NHTSA Vehicle Safety Hotline at 888-327-4236 (TTY 800-424-9153), or www.safercar.gov.