B6100 front PTO shaft stops under minor load

I have a B6100E, 2wd which runs fine. I just re-attached the Woods 348 belly mower which used to work on this tractor. No belt or connection changes. Only change to the tractor is I now have a new, strong battery. Hadn't used the mower for about 9 months. Previously, I had a poor battery and the PTO clutch would slip when well warmed up, but the mower worked fine to that point. But now, when I flip the electric PTO switch to "on", and the clutch engages, it stops the PTO shaft dead in it's tracks and a growling noise come from the engine (a coupling?). But I can turn the belt that runs over the clutch pulley by hand with the tractor stopped with about 20 lb. force -- about normal resistance. What's the problem?

Tried so far: I removed the belt to the Woods mower from the PTO pulley, and when I flip the front PTO switch on, the clutch engages and the unloaded pulley turns. If I apply about 10 pounds pressure by pushing my foot against the turning pulley though, it will halt the whole shaft, with no slip in the clutch. The growling then again comes from the hidden end of the shaft, in the engine.

What's the problem? I appreciate any help I can get on this!

Big Kahuna said:

... since you can stall out your tractor with your foot, I would take the pto off the front and investigate, its on a taper shaft, easy to get to. Big Kahuna

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Actually, the engine keeps running, but it stalls the PTO shaft, and that ugly noise commences and will persist as long as the engine runs and the shaft is stopped.

I'm not saying this proves the bearing is OK. It could well be bad. Just giving you more precise information on exactly what I'm able to stop when I put my foot on it, in case it changes your idea.

I will say that the shaft turns smoothly and quietly in the clutch housing when there's no load, both with the clutch engaged and not engaged. However, if I have the engine off and just turn the disengaged shaft by pulling the belt, there does seem to be a bit of bearing noise. Could be I can just hear better with no engine noise.

Let me know if it still seems to be a bearing problem. I won't doubt it, but it's a strange time for it to show up. Thanks!

kubotasam said:

The front pto shaft has female splines and the end of the engine crankshaft has male splines where they connect. My guess is the female splines on the inside of the pto shaft have stripped out and the noise you are hearing is the splines slipping.

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This proved to be the case. So far, just by sound, the clutch bearings seem fine but the splines are shot.

I'm guessing the way this came about so suddenly is I was jump-starting the tractor on the last mowings, the clutch engaged slowly due to the low amps, and no stress was put on the splines. Once I got the new battery, the little rusty steel holding things tight just wasn't enough and I got an immediate strip of the remaining spline.

Now I'm looking for the fix. There were 2 washers used as spacers between the clutch housing and the frame which I've removed to get more penetration. This may hold until I get a permanent fix. It definitely stops the slippage under moderate load. We'll see what happens when I engage the clutch with the mower belt attached.

Thanks for the help.