The Damper is identified by the Delta number, if you know the Delta number you can use this to find the correct Damper.
Your coupling assembly comes in two parts (refer to the diagram).
The Delta Body will have a series of numbers stamped on it in the location highlighted - we are looking for the number that denotes the delta number. Delta numbers will be 150V, 161S, 200V or 251S or similar.
Use this Delta number to find your replacement damper here.
A coupling damper is a device that improves the quality and precision of your braking when towing by assisting with the gradual application of the brakes both on and off. The correct operation of a coupling damper gives smooth and controlled braking. When the damper has failed, it is very noticeable by the fierce application of the brakes or ‘snatching’ when the towing vehicle’s brakes are applied.
Before replacing the damper it may be worth checking the adjustment of the brake shoes to the drums. Sometimes badly adjusted brakes can have the same effect as a failed damper.