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Discussion Starter · #1 ·
I had the drive shaft fail on my autoconnect drive shaft. Both u-joints failed. Has anyone else had this happen??
 

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That is a MAJOR malfunction!
 

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WOW that is bad,

Had a u joint on the snowblower go ,,,dealer replaced no questions. It had been greased at least 5 times every winter.
 
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My money says something in the shaft was not assembled correctly, allowing it to come apart, I'd raise hell!
 

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I had the drive shaft fail on my autoconnect drive shaft. Both u-joints failed. Has anyone else had this happen??
What were you doing when it failed? The yokes look spread apart, as if a large amount of force was involved. Was it properly greased?
 

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Whoa!

I see this as a result of high RPM's at PTO engagement. Not accusing anyone, just thinking that could be the only reason why this could happen.

If it happened during normal use, there is certainly faulty manufacturing involved.

You don't have anyone out there who wishes you dead, do ya?

Just kidding. I hope it gets taken care of for you.
 

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One of the factories I was responsible for made about 45k drive lines for mid size SUV's.

Only two things will cause an early fail like that. Out of balance or not assembled correctly. I know those of us who like to tinker hate staked bearing joints since there is no good field fix. But on the manufacturing side you can Polk-yoke and have redundant machine checks of bearing press and staking and depth. Trying to validate a cir-clip joint is virtually impossible by machine so it's easier to fix in the field but you run risk of a person not being 100% dead on checking.
 
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Optical illusion?

I'm looking at the angle of the female spline and bearing assembly. In pictures 4, 5 and 6, the assemly "looks" like it's (mis)adjusted/pointed downward at about a 45 degree angle? The female splines should be parallel to the ground and the mating spline shaft on the mower deck. A combination of mismatched alignment and/or high speed engagement of the pto could certainly cause a catastrophic failure such as this. Maybe I'm looking at it wrong, but that's what it looks like to me in the pictures.
:unknown:
 
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I had the drive shaft fail on my autoconnect drive shaft. Both u-joints failed. Has anyone else had this happen??
Just throwing something out here!!!
It looks like the u-joint yokes are spread. Did you by chance engage the mid PTO with the deck in the install position or; when the deck was removed, not have the auto-connect linkage in the raised lock position and then mistakenly have the rear/mid or just the mid PTO engaged with the auto connect linkage hanging in the install position.

In any of these situations, when the auto connect is in the install position, the angle of the drive shaft is at a greatly increased angle. The drive is not intended to be operated at this angle.

I would say, if you engaged the mid PTO with the auto connect in the "install" position, and left this shaft turn for an extended period of time this way, this would do the kind of damage that occurred on your drive shaft.

Engaging the PTO at a high RPM is definitely not the best thing to do, although, these tractor PTO's do not slam in. They are not just an on and off electrical signal. When you switch the PTO on, the current supply to the PTO solenoid is ramped up slowly by the tractor EEC which causes the PTO to engage slowly. This prevents a shock load being applied to drive lines and implement gearboxes.
Now, I am certainly not endorsing the practice of engaging the PTO at high RPM, I am not. I am just saying, if you do by mistake, the tractor is designed to not damage components by a slamming in the PTO.

So, for this reason and the fact that the drive shaft yokes are spread, I would say this damage occurred due to the shaft turning when at an excessive angle. If it was from excessive torque, the u-joint crosses would be broken or the yoke would be twisted, not spread open.

Just some thoughts!! Don't throw anything! :flag_of_truce:
 
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Discussion Starter · #15 ·
I have not seen that before. I bet one failed and the other was destroyed due to the other failure. Either way, this definitely should be a warranty item.

Did anything else get damaged on the tractor? Having that fly around unfettered can cause significant damage.

This also is a reminder to all to keep things lubed.
Nothing else seems to be damaged. I had lubed things. But, must not have been often enough. Still I would not expect it to fail like this.
 

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Discussion Starter · #16 ·
Just throwing something out here!!!
It looks like the u-joint yokes are spread. Did you by chance engage the mid PTO with the deck in the install position or; when the deck was removed, not have the auto-connect linkage in the raised lock position and then mistakenly have the rear/mid or just the mid PTO engaged with the auto connect linkage hanging in the install position.

In any of these situations, when the auto connect is in the install position, the angle of the drive shaft is at a greatly increased angle. The drive is not intended to be operated at this angle.

I would say, if you engaged the mid PTO with the auto connect in the "install" position, and left this shaft turn for an extended period of time this way, this would do the kind of damage that occurred on your drive shaft.

Engaging the PTO at a high RPM is definitely not the best thing to do, although, these tractor PTO's do not slam in. They are not just an on and off electrical signal. When you switch the PTO on, the current supply to the PTO solenoid is ramped up slowly by the tractor EEC which causes the PTO to engage slowly. This prevents a shock load being applied to drive lines and implement gearboxes.
Now, I am certainly not endorsing the practice of engaging the PTO at high RPM, I am not. I am just saying, if you do by mistake, the tractor is designed to not damage components by a slamming in the PTO.

So, for this reason and the fact that the drive shaft yokes are spread, I would say this damage occurred due to the shaft turning when at an excessive angle. If it was from excessive torque, the u-joint crosses would be broken or the yoke would be twisted, not spread open.

Just some thoughts!! Don't throw anything! :flag_of_truce:
PTO has not been engaged with the deck in any other position but down at grass cutting height. I will admit to engaging the PTO at high RPM's. Which could have caused the failure over time. Lessons learned I guess.
 

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Discussion Starter · #17 ·
Wow. Never saw that! Warranty covered that I hope.
Still working on getting things covered under warranty. I will let everyone know how it turns out.
 

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Discussion Starter · #18 ·
WOW that is bad,

Had a u joint on the snowblower go ,,,dealer replaced no questions. It had been greased at least 5 times every winter.
Well, I hope I don't have that happen. Implements are just covered with a 1 year warranty. I have not even used my tiller yet and I have had it a year.
 

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Discussion Starter · #19 ·
I'm looking at the angle of the female spline and bearing assembly. In pictures 4, 5 and 6, the assemly "looks" like it's (mis)adjusted/pointed downward at about a 45 degree angle? The female splines should be parallel to the ground and the mating spline shaft on the mower deck. A combination of mismatched alignment and/or high speed engagement of the pto could certainly cause a catastrophic failure such as this. Maybe I'm looking at it wrong, but that's what it looks like to me in the pictures.
:unknown:
Just an optical illusion because of the way the pictures were taken. Engagement of the auto connect was level with the deck and adjusted correctly.
 

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Nothing else seems to be damaged. I had lubed things. But, must not have been often enough. Still I would not expect it to fail like this.
Krueger86,

Make sure to let us know by posting here on GTT what the dealer says about the failure and if they are seeing this in any other tractors. Also curious as to their opinion why this occurred.

Running the shaft at an extreme angle could certainly cause such a failure, but if it was in a normal operating mode, then my second guess would be a U Joint Failure. I sure hope Deere isn't now sourcing these joints from China to save money.
 
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