Kaufman Trailers is recalling 522 2015-2016 model-year Flatbed Equipment and Wedge Car Hauler trailers because the axle is at risk for disconnecting from the spring hangers, the National Highway Traffic Safety Administration reported.

The trailers were manufactured from April 1, 2015, to April 30 of this year. The lock nuts that secure the axle hanger to the springs may not have been properly crimped, allowing the nut to loosen and detach during operation, NHTSA said. If the nuts fall off, the bolts could loosen and the axle may disconnect from the spring hangers. Any resulting shifting or detachment from the trailer increases the risk of a crash.

Kaufman will provide trailer owners with new Nylock replacement nuts, free of charge.

The recall is expected to begin this month. Trailer owners can reach Kaufman customer service at (336) 790-6800.