Sheared/Broken Crankshaft Keyway.

Cutabove said:

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?

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Oddjob said:

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.

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Auto Doc's said:

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.

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Oddjob said:

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.

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Auto Doc's said:

Hello C.,

A crankshaft (the part alone) is typically not that expensive, but the intense labor to replace it is.

If you are mechanically inclined, have the tools and have the service/repair data it's not that bad of an ordeal. If you are missing one or all the needed prerequisites, you will pay a hefty sum to have the work performed.

Worse yet, is finding anyone qualified.

Most modern small engine techs I come across at dealerships around here are washed up types that could not find a job doing much of anything else. Most of the good ones have moved on to different careers or struggling to go independent.

Like I mentioned earlier, we need some pictures of what you are dealing with, otherwise this is all playing imagination games without any visual content/context.

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Auto Doc's said:

Most modern small engine techs I come across at dealerships around here are washed up types that could not find a job doing much of anything else. Most of the good ones have moved on to different careers or struggling to go independent.

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