I have a Husqvarna YTH20K46 Garden Tractor with 35 hours since new. When I push down on the go forward pedal, it doesn’t go forward or barely tries to move forward but can’t. The book says to replace the motion drive belt. Although that belt feels loose, it’s hard to believe it would need a new belt in 35 hours of use. I have the belt to replace but want to find out if I’m missing a more obvious solution. Could the transmission be low and if so can it be filled without dropping it down from the mower?

If it only has thirty five hours on it, I'd be checking for the cause of the belt being worn. Warranty maybe.