The pendulum may hit the weights if it is twisted or if the clock is not level.
Pendulums can get twisted in shipping or by handling. Howard Miller suggests wearing cotton gloves or using a soft non-abrasive cloth when handling the pendulum. To straighten the pendulum, first remove it from the clock. With one hand, hold the pendulum below the top strap. With the other hand, grasp the pendulum bob. Gently twist the pendulum in the direction necessary to eliminate the twist.
To level the clock, use the adjustable levers under the corners to adjust for uneven floors or carpets.