A poor reconditioning may make the vehicle so strong that it tears itself apart. Much of the undercarriage is made with mortice and tenon joints. Some cracking of paint at these joints is normal. Since the joints are open, they are a weak point for water damage and dirt and grit wear. Most horses are not very fit this time of year, and there is a tendency to overwork the poor babies in a sleigh.
Feet ball up with ice.
There was a special tool, called an ice knocker, for hitting the hoof to dislodge snow balls. Try spraying the sole of the foot with PAM cooking oil spray before driving. At a fast trot these snow balls may smack the dash or floor of the sleigh and make quite a noise. Hold on and keep the horse under control. Just like a toy sled, the sleigh doesn't work well in deep snow.