Mack announced this week that JOST International would supply the company’s fifth wheel couplings and become a standard feature on Mack Pinnacle, Titan by Mack and Mack Granite trucks. 

JOST fifth wheels have been a value-added option at Mack dealerships for more than a decade. 

John Walsh, Mack Trucks vice president of marketing, said JOST was an attractive partner in both the quality of product they provide and their commitment to manufacture their products stateside. JOST components are manufactured in Greenville, Tenn. 

Comprised of only four moving parts, Walsh cited the fifth wheel coupling device’s simplicity and and safety as appealing to including them on their trucks. The fifth wheels use a spring-loaded metal locking bar, which slides into position and secures the kingpin automatically. The bar is equally supported on both sides of the coupling, distributing trailer load equally. Further, the fifth wheel can be disengaged using a 60-pound pull lever.