Mower stopped cutting while I was mowing, need help!

[luthien]

I was mowing today and the blades stopped mowing. I turned it off and looked under the mower and saw the belt had come off. I went to put the belt back on and noticed the pulley was loose. Then I noticed that the jackshaft had slid down and the blade was on the ground. I don't know a lot about mowers. What would cause the jackshaft to slid down? What part do I need to replace? I found a parts diagram with part numbers online (it's how I know what the jackshaft is called, lol). What parts would I need to replace? Any help would be appreciated. Thank you. I have a Murray , Model 4054x92a

 

[DaveTN]

Could be one of several reasons why the jackshaft (spindle) dropped down. One could be the bolts that secure it vibrated out. I saw another mower where the entire jackshaft broke in two pieces, and the pulley flopping around on top. Sometimes the shafts will seize up and fry a belt before you can say "What was that?" By the time you see a cloud of smoke and smell it, the belt is history! Sometimes the deck will crack and the jackshafts will work loose, bolts break or loosen etc.

 

[luthien]

Thank you for the reply. I didn't see a crack in the deck and there was no smoke or anything. I did notice when I slide the jackshaft back up under the pulley looks like some threads were chewed up. I guess I may start by replacing the jackshaft and go from there. Thank you for the help, and if anyone else has an idea it would be greatly appreciated.