Small Engines (Lawn Mowers, etc.): John Deere L118 transmission, john deere l118, google search

Question
After cutting for a while (approx 1hr) my mower quits moving.  I shut her down for while and let it cool I can go back and finish cutting.

The mower is about three years old should the transmission be going out this soon?

Answer
Sad to say, but yes your transmission could be going bad.  You have not told me if its a gear or hydro transmission.  I am assuming its a hydro based on your description of the problem.  Do you pull heavy weight with the tractor?   A drag?  A boat trailer...etc?  A quick google search tells me you should have a hydro.  Check your fluid level...But im thinking you have internal hydro damage that can only be solved by trans repair or replacement.