A towed implement is provided with ground support wheels mounted to its chassis by trailing wheel support arms and respective suspensions including lift cylinders with which are associated damping devices that operate in such a way as to prevent damage to a respective cylinder from rebounding forces resulting when the suspension is being returned to its operating position by the release of energy stored in spring arrangements of the suspension after being loaded by an obstacle engaging the associated wheel. In one embodiment, the spring arrangement includes a damping spring located between an end of the associated cylinder and piston, and in another embodiment, the spring arrangement includes a gas pressure reservoir which, by virtue the operation of a reversing link in the suspension, is loaded both when the wheel is caused to move in a first direction by engaging an obstacle, and when the wheel is moved in the opposite direction by the airborne wheel once past the obstacle.