Important Safety Information

HADCO products are designed with a margin of safety that years of analysis and experience has shown to be more than adequate for their rated capacities, in the service specified. Operation at higher-than-rated speeds or on a terrain or in a service other than specified, overloading, using mismatched components or excessive axle overhang, neglecting to maintain correct tire inflation, or the recommended lubrication frequency, can cause sudden failures with possible serious consequences.

   We recommend that maximum speed and payload, correct tire inflation pressure, wheel bolt (lug nut) torque and bearing maintenance information be displayed along with other safety information in a conspicuous place on the completed vehicle.

   Care should be taken to assure equal side-to-side loading.

   Designers not familiar with factors influencing the stability of towed vehicles (especially at high speed) should contact Hadco Engineering early in the design stage since this stability is dependent on chassis dimensions and weight distribution. Anticipated extremes of terrain or operating conditions must be brought to the attention of Hadco’s Engineering Department.


How to Determine Capacities

Capacity, in all cases, refers to the load measured at the ground.


In assembling running gear components, it is desirable to match the capacities of the axle, tires, wheels, brakes, etc. as closely as possible. The component with the lowest capacity determines the capacity of the entire running gear. For example, if an axle beam rated at 5800 Ibs., is matched with wheels rated at 2600 Ibs. each (5200 Ibs./axle); tires at 5100 Ibs., and brakes at 5000 Ibs., then the axle assembly capacity is rated for 5000 Ibs. If you select larger capacity brakes, say 5200 Ibs., the axle capacity is then rated by the next lowest capacity component (the tires) at 5100 Ibs.


All load carrying components and brakes in this catalog have rated capacities at given speeds. Some components are rated for low speed service only, on specified surfaces. Except where so noted, capacity of components is given at highway speeds, nominally 55 m.p.h. For low speed service ON PAVED SURFACES, WHEEL, HUB and AXLE capacities may be increased: CONSULT HADCO ENGINEERING DEPT.

TIRES may not exceed the ratings shown in the tire capacity charts. Individual tire manufacturers’ ratings may vary slightly from the values shown and should be used when known. Tire inflation pressure must not exceed the inflation pressure shown for the wheel on which it is to be mounted.

BRAKE ratings are not to be exceeded, regardless of speed, without approval of Hadco’s Engineering Department.

SPRING capacities remain constant regardless of speed.


Wheel Bolt (Lug Nut) Torque

Lug nuts should be re-torqued after the first 100 miles of operation and checked periodically thereafter.

Thread Size

Torque Ft.-Lbs