+1
From the description, that sounds like the likely problem. If he's turning
the pulley that's on the gearbox and it won't move the wheels, sounds like
the gears are stripped. The best mower I ever owned from a cutting/mulching
standpoint was a Honda. It has a double blade, mulched better than any other,
left the grass with a smoother cut. But Honda, instead of using a simple
belt/slip arrangement, had an actual 3 speed transmission. After about 6 years
the tranny went kaput. A new one was $130. Even worse, taking the old one
out was a real project. There were so many spacers, widgets, that had to come
off. In the end, it's sitting in parts in the garage. For $180 I bought a
new Sears that someone was selling locally on Ebay. That sucker doesn't cut
as nice, but 10 years later, it's still running. It also has more power than
the Honda, able to go through taller grass easier. The drive mechanism in that
did stop one day too. I took of two screws from the cover plate, saw where the
end of a spring had broken off. One zip tie and 3 years later it's still going
great.