Small Engines (Lawn Mowers, etc.): craftsman model 917.272751 42 18.0 hp 6 speed transaxle, pulley bolt, speed transaxle

Question
right wheel started leaking on the inside.started hearing a clicking noise from the rear of tractor.tractor stopped moving while mowing.won't move in any gear.it will roll in neutral.the drive belt is intact. do you think the trans-axle has broken?the shifter linkage is also intact.

Answer
Can you move the shift lever?  Does it feel like you are engaging the gears?

Does the mower roll if the shift lever is in a forward or reverse?
Are the engine mounting bolts, transmission mounting bolts and the engine pulley bolt tight?
Let me know.
Eric