Hi all, I'm new to this site and would like some advise. I have a Craftsman 26hp 917.27690. My motion drive belt came off trans. Pulley so I replaced belt. Now it won't move forward or reverse. I tried purge transmission but still no movement. I re-checked belt routing. Working fine until belt jumped. Any ideas or help would be helpful.

Highly possible the drive bearing or a pulley threw the belt off. Using utmost safety check and see if the drivers and pulleys are frozen. (usually the bearings, or a lack of lubrication). Do this with your unit OFF and sparkplug disconnected.

Get a manual from this site download http://www.searspartsdirect.com/partsdirect/part-model/Craftsman-Parts/Riding-mower-tractor-Parts/user-manuals/manual-downloads/Model-917276900/0247/1509200?modelNumber=917276900&diagramPageId=00011&documentId=P0602109 Check your belt path and make sure there is proper tension when you release the clutch. You install the belt while someone else holds your clutch in the depressed or forward position.