A grandfather clock is a tall, top-heavy antique whose delicate internal mechanism will be destroyed if you move it without preparation. The heavy weights, swinging pendulum, and fragile chime rods must all be removed or secured, or they will smash the movement in transit. Done in the right order, disassembly protects both the works and the towering wooden case.
Pro tip: Label each weight left, center, and right, since they are frequently different and must go back in the same spots.
Watch out: Never move a grandfather clock with the weights and pendulum still hanging. They will smash the movement.