shift rod and fork not moving freely

I have a craftsman riding mower model#917.275390. Last season while mowing the mower just slowed to a stop but the motor was still running. I have the transaxle on the bench and am noticing that the shift rod/fork doesn,t move freely. Nothing seems wrong with anything else in the transaxle. Should the unit shift easily while on the bench and what would have caused the stoppage last season?

Here is a service manual for your unit. You should be able to shift it on your bench. I'm thinking you may have a seized tranny (caused by moisture) as being your problem. If you are thinking about opening it up please post back, there are a few things you need to know before doing so.

http://www.mytractorforum.com/images/reference/Peerless_Tecumseh_Drive_Systems.pdf

The detent on the shifter can be difficult to move by hand on some of the trannys. have had to use a crescent wrench on a few because of the detents.