To fix pendulum clocks, adjust the casing at the clock's bottom, the pendulum and the clock's beat if the time piece runs too slow or fast. If the clock works intermittently or does not function, bring the arm and hands to the correct position and adjust the clock's beat. If the clock's chimes are incorrect, adjust the hour and minute hands. Adjust the clock's weights appropriately.
Begin fixing a pendulum clock by placing it on an even surface. Use a level to ascertain if the clock is level, and place a 1/4-inch shim beneath the mantelpiece to level it. To level a wall-mounted pendulum clock, shift its casing to the right or left by a maximum of 1/16 inch.
To adjust the clock's pendulum, identify its screw mechanism or weight located near the arm of the pendulum. Rotate the screw by half a turn to the right or left to shorten or lengthen the pendulum, respectively.
To adjust the clock's beat, adjust the position of the pendulum's crutch so that its center motion falls in the clock's center. To do this, gently bend the pendulum's crutch at its center to the position required by hand.
Similarly, if the clock's hands and arm touch each other or are bent, bend them to bring them to their original positions.
To adjust the chimes, take out the minute hand's nut using pliers, and turn the hand until it chimes on the hour. Note the number of strikes, and replace the nut. Then, rotate the hour hand to the number that equals the number of strikes.
If the pendulum clock is tall, adjust its weight on the right side to adjust the chimes, the weight at the left to adjust the strikes and the center weight to adjust the pendulum.