Slip clutch hub stuck on gear box shaft

[clarder]

So my rotary cutter (Woods BB60x) stopped working. It's a model with a slip clutch in front of a shear pin and if there is a sudden impact (wife hits rock for example) or if the clutch is sticky the pin shears instead of the clutch kicking in. So when it stopped working I figured I had sheared the pin and would have to put in a new one...no big deal. When I got down there to do the deed I find that the hub whose flange is gripped by the clutch plates has slid forward such that the hole through which the shear pin goes is not lined up with the hole in the input shaft of the gear box. Again no big deal I'll just slide it back knock out the old pin and all is right with the world. Well it turns out I can only move the hub a little bit forward and a little bit back and not enough in either direction to allow the sheared pin to be knocked out. I took the clutch apart to make fiddling a bit easier and because it probably needed to be disassembled and cleaned anyway and I still can't move the flanged hub any appreciable distance. There's nothing obvious holding the hub to the input shaft, no set screw or bolt of any kind and it sure looks like it should just slide off (otherwise how would you replace worn out clutch parts). I'm worried the input shaft might be bent but I'm sure hoping it's an easy thing I just haven't thought of.

Any thoughts would be greatly appreciated.

Thanks,

Chris

 

[kebo]

Welcome to the forum! Pictures always help to show the problem.

 

[greg_g]

Slip clutches are upgrades from shear pins. What you're referring to as a "shear pin" is (or should have been) simply a hardened fastening bolt. If it broke, the bolt itself was too soft to begin with (I use GR8) and/or the slip clutch itself was mal-adjusted/frozen. What's likely happened is that the impact caused damage or distortion to the clutch hub and/or to the transmission stub in the area(s) where the 4 holes intersect. A broken bolt can cause damage to the hub/stub metal surrounding one or more of the four holes. The resistance is likely interference from these damaged/distorted metal sections clinging together. Less likely is that there could be bolt fragments still in there that have worked their way in between the hub and the stub. Assuming that's not the case, the impact technique you describe should eventually pull the hub past the interference. Be prepared to see some damage revealed though.

//greg//