I have a Howard Miller wall clock with a Hermle 351-030-A, 8 day Westminster Chime Movement with 34 cm pendulum. The clock is approx 20 years old and looks brand new. The movement was professionally cleaned and serviced approx one year ago and it keeps time beautifully. For about the last 8-10 months, after winding the clock I have had to tilt it noticeably to the side to get it in proper beat however.
If I level the clock (using a high quality level), the clock is noticeably out of beat (beat very uneven). For me to get the clock in beat, I have to tilt the bottom to the right about 4-5 degrees after which it looks noticeably cocked on the wall.
Sam, the is a common occurance. Contrary to popular convention, a clock does not always have to be level to be "in beat", which means an even tick....tick....tick..tock. When a clock of this type (modern production clock) leaves the factory or clock shop, it should have been set in beat when level. But sometimes it gets knocked out of beat. There is an adjustment to correct this. To get a little technical, the pendulum is attached to a hanger (also called a leader) which hangs from the small suspension spring at the top. The leader is connected to the crutch arm which comes out of the top back of the movement. It swings from one side to the other. The crutch is part of the verge assembly that, on this model, can be slipped to correct. If you remove the pendulum you can gently move the hanger and crutch from one side to the other until you feel it stop. When it is out of beat you will find that it swings further to one side than the other. If you move it to the "short side", you will find that you can slip it a little further. So you want to slip it one way or the other until it has equal movement from a vertical line to both sides. Once you learn how to do this you can actually do it from the front of the clock with the pendulum attached. Set the clock on the wall until it looks level and matches the level of the room (I occasionally find rooms are out of level and the clock has to be tilted to look right.) You then make the pendulum adjustment until you hear that it is in beat. I always suggest to the clock owner that when the clock is set and running in beat that they make a mark on the wall near the bottom side of the clock. This is so that when the clock is bumped or tilts when opening the door to wind or set it, it can be put back in the same position. As far as bending the leader is concerned, this is for older clocks that did not have a slip verge, so this does not have to be done.