If you are not able to locate a gear by spec, a couple of possible options. The best may be an experienced dealer that may have one on the shelf. A quick look of that model series ( a few more digits for the complete build model # needed to be sure) shows a seller had a new one on Ebay that just ended w/o a sale (though imperfect for $99 shipped). He may deal? Normally one would replace both gears at once anyways. Also, you may try a Toro dealer. MTD had built some Toro Stage for a number of years and some of the MTD builds have the gear available. Of course, watch over the gear box bearings and input shaftt bearings.