Mack Trucks, Inc. (Mack) is recalling certain 2015 CHU, CXU, and GU trucks manufactured June 4, 2014, through June 18, 2014. In the affected vehicles, the bolts that attach the seat belt to the seat frame may not have been torqued to the required specification. This could cause the bolts to loosen over time, allowing the seat belt to detach.