A: Ride height is the distance from the center of the axle to the mounting surface of the suspension (i.e., the bottom of the trailer or slider frame). An easy way to determine ride height is to measure the distance between the mounting surface of the suspension and the top of the axle, then add half of the axle's diameter. For example, on a five-inch diameter axle, add 2˝ inches to the measured distance between the suspension mounting surface and the top of the axle.

A: Yes. You now have the option of ordering a SURELOK® reftrofit kit specifically for tapered beam HKANT 40K models. This retrofit kit includes weld-on beam extensions required to accommodate SURELOK®. In addition to SURELOK®, Hendrickson offers other loading dock solutions. Please refer to Hendrickson publication L816, Trailer Loading Dock Terms and Solutions, for more details.

A: After the warranty period expires, just continue to inspect the wheel-ends as recommended in Hendrickson publication L496, Wheel-End Maintenance Procedures. There are no serviceable internal components in the HUS™ hub assembly. The HUS™ hub is built and installed with such a high degree of accuracy that using the wheel-end beyond the stated warranty period, without doing anything to the wheel-end (other than scheduled inspections), should not be an issue.

A: The integrity of the pivot connection depends on proper clamp load. The shear feature of the shear-type bolt used in the pivot connection establishes the proper clamp load. Torque value is simply a means to communicate what the proper clamp load should be when the shear feature is not used. Accurate torque validation can also be difficult to determine because you have to make sure the pivot hardware does not slip during the process. Hendrickson uses random sample testing on every received lot shipment of pivot bolts. One of the routinely checked pivot bolt characteristics is the clamp-load-to-torque value. This value is closely monitored by Hendrickson, and any samples measuring outside of our acceptable clamp-load-to-torque-value range causes the entire lot to be rejected.

A: Actually, older compressors could also deliver the higher pressures. All Hendrickson air actuators were designed/specified with regard to these higher pressures, therefore the higher pressures will have minimal impact.

There are valves that are designed as pressure limiters. They are basically factory set pressure regulators that have no adjust mechanism. They are inexpensive and if desired, could easily be used inline to limit pressure to a preset maximum.

A: Either is fine, but Hendrickson prefers (not recommends) a service brake priority valve over a spring brake priority valve. The service brake priority valve ensures that there is pressure in the onboard air tank before the trailer is able to move. This helps to reduce the length of time a loaded trailer can be operated without sufficient pressure in the air springs. The service brake priority valve also helps to reduce the possibility of SURELOK's mechanical support arms being held in place, after the trailer parking brakes are released, due to friction between the SURELOK arms and the rear suspension beams.