George Sturmon suggests that urethane bushings have become more of a “mainstream” option for the trucking industry, and it is hard to argue with the owner of ATRO Engineered Systems. His company began producing the bushings for Hendrickson beam-style suspensions in 1987 and gradually has expanded the product line to include everything from torque rod bushings to transmission mounts.
The story is echoed by a number of suppliers. Urethane now is being used to produce everything from hood and cab mounts to the bushings for torque rods and suspension systems. And it can be found in suspensions with labels as diverse as Reyco Granning and Hendrickson.
The choice often is part of a bid to extend component life.
Unlike rubber, for example, urethane can withstand the chemical attacks of oil, hydraulic fluid, brake fluid, antifreeze and de-icing compounds.
“The only chemicals that will affect polyurethane are chemicals that have no business being anywhere near a vehicle,” says Energy Suspension Sales Manager Kevin Taeger, referring to solvents. In fact, he suggests that a urethane bushing can last 10 times longer than its rubber counterparts because of the decisions that are made in a laboratory to affect shape memory, rebound, hardness, tensile strength and elongation.
“Normally you have five different ingredients that make up the urethane. The beauty of urethane is you can adjust those five different chemicals,” says Sturmon. “You can change the tensile strength. You can change the tear strength. You can change the elongation
