What could cause the pto clutch to fly off a narrow frame?
 

My buddy has a 124. He was plowing snow last night and he heard a loud Bang and then no other issues. So he pulled it back in the garage and looked under the hood. The pto clutch was laying between the engine and the frame.

From the picture he sent me it appears his pto engagement rod was not connected. Could the engagement lever flopping around cause it to fly off? What am I going to need to do to fix this for him.

The engagement rod has nothing to do with the PTO staying on the shaft. The PTO Bearing with it's "locking collar" keeps the PTO in place.

You will have to examine the engine shaft for damage, and perhaps a new PTO Bearing.

So most likely he should have used removable loctite on the set screws? Hopefully it'll be an easy fix as it'll be mowing time before you know it.

So there is no chance that the fact that the lever that holds the pto button was just free to flop around near the pto clutch? Like that couldn't of gotten hung up on anything?

The lever may have held it in place but it just would have hidden the real problem.

Possibly the set screws backed out of the PTO or the eccentric wasn't tightened for the PTO bearing. It is possible there was catastrophic failure of the PTO bearing but that isn't very likely.

To put it simply, there is a bearing on the shaft coming out of the front of the motor. That bearing is held in place on the shaft by a locking collar and a set screw. This link will explain that....

http://cubfaq.com/bearingcollar.html

Then the PTO clutch slides onto the bearing and is held onto the bearing by three double sets of allen screws. Three holes, first allen screw in hole locks PTO to bearing, second allen screw on top of first locks first one in. This link shows that.....

http://cubfaq.com/mechanical_pto.html

This links shows PTO specs....

http://onlycubcadets.net/forum/showthread.php?t=9

Sounds to me like either the allen screws backed off and the PTO assembly slid off of the bearing, or the bearing disintegrated and everything fell apart. The engagement arm has nothing to do with everything staying together. If you need to get those allen screws out, you may need to use alot of penetrating oil depending on age, and don't forget there are TWO IN EACH HOLE. Good luck.

Nice post Ironman.

:beerchug:

I put a PTO on my tractor so I know how it works. I am just trying to figure out why it happened. I know he had his off and then re-installed it about a year ago so maybe he forgot to put in the 2nd set of screws. Either way I'll get it fixed for him.

Simple, it's because he didn't want it off haha. I wanted to take mine off and had to cut it off with a huge cut-off wheel.

Man that is so true.