The PTO on my JD Ztrak 830A has just started shutting down while I'm mowing. It's not too hot. mid-80's lately, and if I shut down the engine, then re-start, it will work again. The first time it happened, I had been mowing for about 1/2 hr and I saw no indicators on the status panel, it just shut off. Grass wasn't particularly heavy. The second time it happened, I was mowing for about 15 min, and hit some heavy grass (mulching kit installed) and it shut down. The first time, I just parked the machine. The second time, I shut the engine off, re-started, then engaged the PTO and it started right up. The PTO has less then 100 hrs on it, since I replaced it last year. My thoughts to date are that it is some kind of sensor (heat) that is supposed to shut down if it gets too hot or an intermittent switch problem. Haven't really started troubleshooting on the machine yet, but will soon. Thought I would run it by you guys first. Thanks!