Mechanical override coupling 2000kg, NO brake lever. Four bolt holes. Holes are 55mm centres apart, across the coupling. Holes are 185mm centre to centre from front to rear
The principal of this type of coupling is a sliding shaft attached to the tow ball housing of the coupling. As the tow vehicle slows down the force of deceleration is passed through the coupling shaft and pushed either on a mechanical linkage (for mechanical brakes) or on a linkage connected to a hydraulic cylinder providing hydraulic pressure to a braking system (hydraulic brakes).
This type of coupling is most efficient if the ball load is not excessive and when load levelling devices are not used, as these devices impede the smooth operation of the coupling, ultimately impeding the braking performance.
When reversing, the attached collar would be fitted to prevent inadvertant brake application. The collar should be removed from the shaft during normal towing use.