Abstract: This dolly frame has a cross member upon which a pair of ground wheels are rotatably mounted and from which laterally-spaced opposite side members project forward. These side members terminate in wedge-shaped coupling members pivotally connected to coupling member adapters permanently secured to the rearward portion of the towing vehicle chassis, thereby providing limited rise and fall of the dolly relatively to the adapters. The center of a transverse leaf spring mounted on the cross member engages the lower end of a trailer hitch ball structure mounted on a cross-head which is in turn connected to a shock absorber to thereby dampen the oscillation of the leaf spring and thereby eliminate the pitching otherwise transmitted to the towing car as a jerking motion back and forth when the dolly hits a bad bump.