A towed, agricultural implement includes an undercarriage supported on ground wheels that are attached to the undercarriage by trailing support arms. An adjusting motor is coupled between the undercarriage and a transverse torsion rod having its opposite ends coupled to the wheel support arms by braces. The adjusting motor is selectively operable for raising and lowering the ground wheels relative to the undercarriage, with the torsion rod acting to absorb shocks between the undercarriage and the wheel support arms.