Another point warranting attention here is the spring in the override type of coupling a weak spring will cause a “shunting movement” and this in time will affect the power transmission of the car.
The attachment for the car should be absolutely rigid, any movement here will have an adverse effect on trailing. Angle iron of at least 2x2x¼ in. is most suited as a reinforcement inside the bumper bar. It is advisable to refit with 2 inx½ in. flat steel (on its edge). Three ½ in. bolts have proved sufficiently strong to carry the angle bracket to which the ball is attached.
The caravan springs are another feature having considerable effect on trailing. Its is recommended to use a short spring with sufficient camber to ensure clearance – length of springs most suited are 34 in. to 36 in. Springs may be over or under – slung, and no major advantages are gained by the use of “drop axles” However , it is most desirable to fit the spring s as close as possible to the wheels therefore, does not tend to bend the axel. The greater number of bent axels are caused by fitting springs of insufficient camber.