I have a 2320 Kubota 4 wheel drive lawn tractor I bought in 2014. Recently the Hydrastatic foot pedal has started not returning to the neutral position. I have checked for trash around the levers and greased the hinge joint but to no avail. The pedal has to be in the neutral position or it won't allow the starter to engage. I have to use my hand to rock the the foot pedal back and forth to find the neutral position. It is not the switch because the tractor creeps in what ever position the pedal is stuck in. I also have an older B 1550 that does the same thing. My Kubota dealer is 60 miles away. Any one have any suggestions.