Had about a year. Can't change deck height at will. Most time foot pedal goes down about half way and at that level I can't turn select know to most heights. Usually 3.25 or 3" only. About 6% of the time it works normal and I can select any height. Took into dealer, they say nothing found. It worked fin on the trailer, but as soon as I got it off trailer foot pedal would not go top full extension . Any suggestions? Thanks