Small Engines (Lawn Mowers, etc.): Craftsman Riding Mower Transmission, rear fenders, trans model

Question
I bought this mower used 3 years ago. I don't use it in the summer, only in the winter with the snow blower. When I bought it, it had just had a new transmission put in. Worked great the first year, some problems the second year. This year, the transmission seems to be off. It seems like the stick has shifted so that all the gears are one slot down (1=2nd gear, N=1st gear and R=N). Not sure if I need to bring it in or of I can fix it myself. I can do minor repairs, but don't have the time or knowledge to do anything major.

Answer
I need the mower model nubmer found on the Craftsman sticker.  The sticker is about the size of a business card and usually located under the rear fenders or seat.

The transmission make and model would also be helpful.  The trans model is either on a sticker or metal plate on the transmission.

Send me the info so I can look up your trans.

Eric