Help with Root Cause Analysis. 2528 PTO Idler Pulley Shaft Failure

[blue280z]

Hi,

My 2518 Cub Cadet had a catastrophic failure of the PTO idler pulley shaft (just below the front engine area). I'm 100km away from the tractor but will take photos later today. Here is a quick internet image of where the failure happened.




The tractor is new to me but used with 200 hours. The belt broke while using the 48" mid-ship mower deck. When going to install the new belt I noticed the shaft was broken and the area marked in red looked like someone took a grinder to it. I can not think of how a belt could grind metal so I ruled it out.

The previous owner used a front mount snow blower so I looked at that attachment but could not see any wear in that area.

I ordered new parts but will need to buy a cordless grinder to get the parts off as the inner bolt is fused to the sleeve on the right side, and the bearings are the only place to grab on the left. The current location of the cub (our 6 acres with an old building) has no AC power.

All help, suggestions on what could have caused this failure is appreciated. My guess is that someone or something ground/damaged the shaft in the past and it finally let go.

[R Bedell]

First. welcome to OCC........

Can't offer a reason why, but replacing the shaft is needed.

I can't say that the Mule Drive Shaft has had issues.

[Sam Mac]

It is not a shaft. It's a spacer that fit's between the two pulleys with a bolt through the center.

https://www.cubcadet.com/en_US/ari-p...3e5f6df63fda/y

[blue280z]

Originally Posted by Sam Mac

It is not a shaft. It's a spacer that fit's between the two pulleys with a bolt through the center.

https://www.cubcadet.com/en_US/ari-p...3e5f6df63fda/y

Thanks. I am aware of this. In fact the outer spacer is fused to the inner bolt so that is my current challenge to remove.... the slow passage of replacement parts in the overloaded/understaffed logistics world is also a factor.

[ol'George]

Theory:
Idler bearing seized/failed do to either little grease or it just wore out.
It then spun on the bolt and or spacer, till it wore enough to cause bolt failure.
In the outback,possibly a hack saw would cut through needed material and only recharging needed would be favorite beverage provided by the operator.
Take two blades just encase operator feels stronger than normal.

[blue280z]

Thanks George!

That sounds like the most plausible scenario. The replacement parts have not arrived yet so I'll be heading to the machine when they come in. I'll take a photo then. I'll also inspect the pulley to see if it was riding on the spacer. The inner hole where the bearing sits should be quite worn.

[blue280z]

Originally Posted by ol'George

Theory:
Idler bearing seized/failed do to either little grease or it just wore out.
It then spun on the bolt and or spacer, till it wore enough to cause bolt failure.
In the outback,possibly a hack saw would cut through needed material and only recharging needed would be favorite beverage provided by the operator.
Take two blades just encase operator feels stronger than normal.

You got it right George. The pulley bearing failed (outer race) and the pulley body ran on the spacer/bolt until it wore through and broke.

[blue280z]

Dewalt Tools are Great!

[Sam Mac]

That had to make some entertaining sounds.

[ol'George]

Originally Posted by Sam Mac

That had to make some entertaining sounds.

That would of been one hell of a "spark show"
Many a Combine burned to the ground while running wheat from a failed bearing this time of the year.