My new Z830a is on it's 4rth transmission belt with only 85 hours on the clock. Dealer also replaced the idler this time because it had sharp burrs, but I think those came from when the belt broke and the idler slammed into something else at full speed. I can't believe this machine weighs 1300lb. dry without operator, goes 11-12 MPH, yet has only a puny 1/2" belt to drive the transmissions. That wimpy little belt should be on an alternator or fan on a car, not propelling 1300 lb of mower with 66 lb of fuel and 275 lb of operator. OK so maybe I could lose a few lb. but my God, trying to propel 1600 lb. with a 1/2" belt just defys engineering common sense. If you own one of these lemons, welcome to the house of pain. Oh, the deck lift pedal goes lame from a bad bushing (did it on mine and a loaner) and also the high-lifts are so strong, they lift pea gravel and shatter your customer's windows. (2 windows broken in 14 years of mowing, both this week courtesy of my Z830a).