Abstract: A clamp (10) for mounting a packaged engine-driven electrical generator, or generator set (70), to a transport trailer (80). The clamp has two major components, a frame member (12) and a clamp member (13), both generally L-shaped. The base (21) of the frame member is securely attached to a frame member (72, 73) of the generator set. The base (31) of the clamp member extends through a fulcrum slot (25) in the frame member. When in the engaged position, a nut (14) and bolt (15) connect the frame member riser and clamp member riser. The clamp engages the flange of an I beam 81, part of the chassis of the trailer, between the base portion of the frame member and the toe (34) of the clamp member. Tightening the nut and bolt causes the clamp to clamp securely to the I beam.