My wife inherited a grandfather clock from her mother. It has run well for many years, but in recent months it has been running fast. I have let the pendulum down as far as it will go and the clock still runs fast. Attached are pictures. It is a Howard Miller and was procured in about 1986. I disassembled, cleaned, oiled and reassembled the movement and could not see any issues. Can anyone tell me why the clock might be running fast?