The new pivot pin is on top, the broken pin is on the bottom. The pin is about 13" long and 1/4" in diameter. It broke at 1 of the predrilled holes clip hole. I don't know what caused it to break. Maybe it's old age. The machine is 14 years old and has been through heavy use in cold weather. It

This picture shows the core of the Arien's transmission. The drive belt and pulley are attached to metal plate that swings back and forth on the pivot pin as the drive lever on the handle bar is squeezed and released. The friction disk is connected to a set of chains and gears that turn the axle. The disk rotaes when it comes in contact with the pully and that in turns drives the gears that rotate the axle. The pivot pin, if it were present, would be holding the drive belt and pully perpendicular to the friction disk.

This picture shows the core of the Arien's transmission. The drive belt and pulley are attached to metal plate that swings back and forth on the pivot pin as the drive lever on the handle bar is squeezed and released. The friction disk is connected to a set of chains and gears that turn the axle. The disk rotaes when it comes in contact with the pully and that in turns drives the gears that rotate the axle. The pivot pin is holding the drive belt and pully perpendicular to the friction disk.