If no pendulum is attached your mantle clock may be regulated by a balance wheel which is operated by a spring.
How to fix a wall clock pendulum.
Check to see if the spring is in working order.
Bend the clock verge back into position with a set of needle nose pliers instead of shimming your out of beat clock.
Brushing the mechanical works with a soft brush such as a paint brush should dislodge any dust or dirt.
If your pendulum clock has lost its best beat you can get it back in time with a bit of beat education and simple tools.
Lengthen the pendulum by turning the screw mechanism to the left 1 2 turn.
Too low causes the clock to run slow.
Shorten the pendulum by turning the screw mechanism to the right 1 2 turn.
Open the battery compartment with your fingertips and nails or use a screwdriver to open it.
If dried oil is visible gently brush it away.
The verge is the wire from which the pendulum hangs.
Dried oil and debris can clog and stop the clock mechanism.
Inspect the battery compartment for corrosion you will likely see a bloom of blue and white or green and white mold around the ends of a battery.
Open the back door of the clock carefully with a small screwdriver.
A pendulum too high causes the clock to run fast.
Step 2 put on gloves and pull the batteries out with tweezers or tongs.
Locate the adjustable weight or screw mechanism near the pendulum arm.
Understanding the mechanics of your cherished time piece will help you fix problems that can occur without having to drag the clock to a repair specialist.