Click here to write a Letter to the Editor. endrickson Trailer Suspension Systems, a supplier of truck and trailer axles and suspensions, said it has formed a new unit to handle business for such products as tire-inflation and suspension-control systems.The unit will also manage such products as trailer height control valves, lift axle controls and dump valves, Hendrickson Thursday said in a statement.The controls business unit will be headed by Matt Wilson, who joined Hendrickson 2005 as a program manager in the marketing group.