Finish mower problem

[goldchaser]

Got a problem with my finish mower. The PTO driveline needs replacing. The mower is a yanmar brand, ym 45, I think is th model.
Anyway, I cannot figure out how to remove the driveline from the mower.
Most I have removed before on other implements were just pinned and then slid off. No pin on this one though there is seemingly a hole there for one but probeing in the hole just hits sold metal, I presume the shaft to the mower tranny. So what is holding this sucker on there?
It wont move near as I can see. Help? The only other option I can see is opening the gearbox and see what is up...didnt want to do that since it has been many a year since that thing has been taken apart. Also, I think you all can see why I have to replace the driveline.
Here are a couple of photos.

 

[fogtender]

You can just pull off the U-joint itself. There is two snap rings (more like a "C" clip) that holds the needle bearing housing in from being spun out. You can install a new one on the machine with a C-clamp, but if you have never done that before is may be a bit of a hassle.

The hole in the shaft is for a "Roll Pin", take a straight punch of that size hole and drive out the roll pin, and then pull the whole Drive shaft assembly off and take it to a shop to replace the bad joint, but I would do both ends if one is bad, the other isn't too far behind.

Here are some photo directions if you want to repair it where it is at.

 

[goldchaser]

Thanks for the quick reply. I had tried driving that pin out. All that happened was I ended up bending my punch...go figure.. Didnt know those things would bend. And couldnt seen any movement inside on the pin thats supposed to be there. Thats why I figured it could just be the shaft of the mower.

Just a thought. Is it possible that the joint has drifted around on the shaft so that the pin is not actually visible? Not sure of the mechanics involved at the moment...brain dead.

Next effort will be to just try removeing the c clips and pull it apart there. I think I will leave it for tomorrow though. The heat has kinda sapped me this afternoon. Wasnt able to work on it in the shade which was dumb because I could have lifted it with the tractor and moved it into the shop.
Oh well...one of those days.

 

[mla2ofus]

Don't know how long it ran w/ the cup gone on the one journal. May be too wallowed out for new cup to fit tightly.
Is that shaft round that the gear box yoke fits on?
Mike

 

[goldchaser]

Don't know how long it ran w/ the cup gone on the one journal. May be too wallowed out for new cup to fit tightly.
Is that shaft round that the gear box yoke fits on?
Mike

It didnt run that long. I felt the change in vibration not too long afterwards but even that short time could have been too long.

The shaft is round.

 

[urednecku]

Is there a chance there is an allen screw in there?

 

[fogtender]

Is there a chance there is an allen screw in there?

Could be, but if so, you would see the threads at the top edge of the hole, if the hole goes all the way though to the other side, it will be a roll pin.

 

[fogtender]

Thanks for the quick reply. I had tried driving that pin out. All that happened was I ended up bending my punch...go figure.. Didnt know those things would bend. And couldnt seen any movement inside on the pin thats supposed to be there. Thats why I figured it could just be the shaft of the mower.

Just a thought. Is it possible that the joint has drifted around on the shaft so that the pin is not actually visible? Not sure of the mechanics involved at the moment...brain dead.

Next effort will be to just try removeing the c clips and pull it apart there. I think I will leave it for tomorrow though. The heat has kinda sapped me this afternoon. Wasnt able to work on it in the shade which was dumb because I could have lifted it with the tractor and moved it into the shop.
Oh well...one of those days.

I would doubt that the shaft would turn, there is a keyway on the shaft and that would only allow it to pull in or out. There "May" be an allen set screw like urednecku said, but I couldn't tell by the photos if there was threads down into the hole. If the hole goes all the way though, then it prob. has a roll pin, if not, then it may be an allen set screw and an allen wrench may unscrew it.

I think that if you can have someone to give you a hand, removing the two "C" clips and driving the U-joint out is a good way to go, you can put grease in the new cups of the new U-joint to hold the needle bearing inplace and use an C-clamp to press the new ones in, then reinstall the C-clips to hold them in place.