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.

 

[Cutabove]

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.

Thanks for your input, I will do some follow up including how many hours are on the Hobs meter. A new Crankshaft doesn’t seem to be terribly expensive. A single Piston Assy is more that the Crank.

 

[Cutabove]

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’m not sure, I purchased this from a 3rd party not the original owner. The mower is very dusty but seems like it has very little actual engine time. There aren‘t even any rub marks or scrapes on the 60”deck. I would say it has never been in commercial use.

 

[Auto Doc's]

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.

 

[Auto Doc's]

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.

 

[Tiger Small Engine]

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.

I have a Dixon zero turn with a damaged crankshaft. Customer installed new PTO clutch themselves and did not tighten and torque it down correctly. I ended up with it as a result, and have not had time to remove and replace engine with good used Kawasaki, or replace crankshaft with new one. Crankshaft has to be in good condition obviously to properly accept and maintain PTO clutch. Mower is probably only worth around $1500 or so with everything good and working. Hopefully I can fix this winter and sell in the spring.

 

[StarTech]

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.

Now you have hit squarely the nail on the head. Most the shop techs around here can barely get out a wet paper bag with both end open. Now there are still some local mechanics take pride in their workmanship that willing to learn or at least the customer to someone that has the needed knowledge.

It is embarrassing as heck to have a JD tech to tell a customer that his does not have an oil pump when there is an oil filter staring them in the face. Just one example over the last few years.