Sheared/Broken Crankshaft Keyway.

[Cutabove]

Engine: ZT740-3048.
Please, looking for help or input with above stated issue. I purchased a 2020 Maverick in a box so to speak that has potential I believe. In what I would call it very clean condition, however! Kohler powered with a sheared off Crankshaft key-way broken out right where the blade clutch mounts. Has anyone here experienced this in the past and or replacement of Crankshaft?

thanks in advance

 

[Oddjob]

Please, looking for help or input with above stated issue. I purchased a 2020 Maverick in a box so to speak that has potential i believe. In what I would call it very clean condition, however! Kohler powered with a sheared off Crankshaft key-way broken out right where the blade clutch mounts. Has anyone here experienced this in the past?

Wow. How did that happen? Someone replace the soft medal key with steel? Manufacturing defect? If it hit something it must have been quite a bang. Is the crankshaft bent? Short of replacing the crank, all I can think of is to put some weld on it and grind/file the excess away. I’d make a key out of brass and stick it in the keyway so no weld gets into the slot. Weld does not stick to brass. But I’d make sure the rest of the engine is ok before addressing the keyway issue. I hope someone more knowledgeable can offer better assistance.

 

[ILENGINE]

Wow. How did that happen? Someone replace the soft medal key with steel? Manufacturing defect? If it hit something it must have been quite a bang. Is the crankshaft bent? Short of replacing the crank, all I can think of is to put some weld on it and grind/file the excess away. I’d make a key out of brass and stick it in the keyway so no weld gets into the slot. Weld does not stick to brass. But I’d make sure the rest of the engine is ok before addressing the keyway issue. I hope someone more knowledgeable can offer better assistance.

I don't think he is talking about the flywheel key shearing..He is talking about the keyway on the pto end of the crankshaft being broken where the electric clutch mounts. I suspect the clutch was loose and then hammer broke the crank keyway.

 

[Auto Doc's]

Hello C.,

A couple of pictures would be helpful.

This may not be to terribly bad. I have repaired quite a few over the years without replacing the crankshaft.

In the past, I have seen this kind of damage caused by someone who did not install the PTO clutch correctly or tightly. The formed key in the PTO clutch tends to hammer out the crank groove.

The keyway is what prevents rotation of the PTO under extreme shock load. but the torqued center bolt is what provides the needed clamping force to keep it from moving.

Short of replacing the crankshaft, there is a chance it can be MIG welded and redressed without removing the crankshaft if a qualified welder/ machinist is paid accordingly.