Two recalls, affecting nearly 1,700 Mack trucks have been issued, according to the National Highway Traffic Safety Administration.

The largest involves 1,155 model year 2013-2014 CHU, CXU, GU, LEU, and MRU vehicles manufactured with pro-torque axle spindle nuts from August 28, 2012, through August 16, 2013.

The pro-torque nut may not have been installed correctly, which may result in a loosening of the nut.If the nut comes loose, the hub assembly may separate from the vehicle, increasing the risk of a crash.

Mack Trucks will notify owners, and dealers will inspect and repair the vehicles, as necessary, free of charge.

The recall began on November 12, 2013. The recall number is SC0371.

The other recalls involves 535 Mack model year 2014 CXU and GU vehicles manufactured May 10, 2013, through June 12, 2013.

The upper and lower steering shaft pinch bolts may have not been torqued to specification. This may cause the steering shaft to come loose which would result in a loss of steering control.

Mack Trucks will notify owners and dealers will inspect the steering shaft pinch bolts and retorque them as necessary, free of charge.

The recall is expected to begin by December 9, 2013. Mack's recall number is SC0372.

Owners may contact Mack Trucks at 1-336-393-2000.