Hillsdale Township (Michigan) man killed trying to free bulldozer

[jagyzf]

I picked up a new made in USA 2 5/16 ball for use on my tractors in pulling my dump trailer. First time use when I dumped the trailer the trailer hitch jumped up with the ball still secure in the hitch. The threads had stripped out of the nut - very strange failure. Everything felt like it tightened up fine, no sign of yield and the stud end went all the way through the nut. No idea where the nut came from - it was in the package with the ball. I never before bothered with safety chains on the tractor because there is nothing in the area to hook them too but the drawbar and I mistakenly assumed if it went it would be the drawbar falling off for some stupid reason. Now I have a clevis in another hole on the drawbar so I can safety chain all my trailers. Our 2 John Deeres already have a safety chain attaching point but not the Kubotas.

That is a strange one, not in that application and never with a new nut, but I have seen threads pull out of nuts before.

 

[MHarryE]

That is a strange one, not in that application and never with a new nut, but I have seen threads pull out of nuts before.

Another odd coincidence is my partner called me to say a wheel fell off our 30' cultivator 2 days before. He picked up new wheel bearings, seal and castle nut from the local shop and I met him in the field to put it back together. He held the wheel while I tightened the nut and as the bearings started to snug up all of a sudden I could easily spin the nut with no more bearing tightening. Being in a hurry to get going before the rain hit I figured that the inner threads were damaged when the bearing failed so I slapped on a heavy flat washer and tried again. Same thing. Took the nut off and saw that the threads had pulled out . This was tightening a 3/4" fine thread nut using a standard length 1/2" drive ratchet so no way was I putting very much torque compared to what is should have been able to handle. Fortunately we had that size nut at the farm so we quickly got going but I heard in the past about bad fasteners getting into the system. Never thought I'd run into it twice in 2 days on 2 completely different products.

 

[chad22]

That's definitely sad. I've pulled stuck vehicles with a chain attached to a ball. Never would've thought something like that could happen.

Chad

 

[JDgreen227]

That's definitely sad. I've pulled stuck vehicles with a chain attached to a ball. Never would've thought something like that could happen.

Chad

Chad, many people feel that pulling with a chain is safer because they don't stretch and if a chain breaks or comes loose from an attachment point, the weight will make it drop...while a strap will stretch and being lightweight, can act like a slingslot.

 

[Marveltone]

Part of the problem is the practice of hooking a chain/strap/rope to a ball. Balls are designed to carry a vertical load, not horizontal. I carry a clevis to put in my drawbar for such operations. I believe the clevis is a better option as it pulls from both top and bottom and spreads out the load.

Joe

Sent from my XT907 using TractorByNet

 

[GManBart]

Part of the problem is the practice of hooking a chain/strap/rope to a ball. Balls are designed to carry a vertical load, not horizontal. I carry a clevis to put in my drawbar for such operations. I believe the clevis is a better option as it pulls from both top and bottom and spreads out the load.

Joe

Sent from my XT907 using TractorByNet

When you hook a trailer up to a ball, it's most certainly carrying a horizontal load. That's why the higher it's rated, the larger the bolt diameter is.

 

[Marveltone]

When you hook a trailer up to a ball, it's most certainly carrying a horizontal load. That's why the higher it's rated, the larger the bolt diameter is.

Some horizontal rolling load, yeah, but not the snatching an immovable object from a sticky mud hole load. That's a whole other level of force. A proper shackle is still much stronger for that kind of operation.

Joe

 

[JDgreen227]

Some horizontal rolling load, yeah, but not the snatching an immovable object from a sticky mud hole load. That's a whole other level of force. A proper shackle is still much stronger for that kind of operation.

Joe

I agree that hitch balls are better suited and most likely rated for ROLLING loads, not a fixed one.

 

[oosik]

Well. I use commercial nylon tow straps on the tractor(shackle on drawbar) and ATV and have never experience any problems. Then again, I've never tried to unstick a bulldozer with a pickup. Had the neighbor come pull my mud-stuck tractor out. But that didn't require much pull at all until my tractor caught dry ground and was on its own again. Something beyond the normal is happening in these cases.

 

[GManBart]

Some horizontal rolling load, yeah, but not the snatching an immovable object from a sticky mud hole load. That's a whole other level of force. A proper shackle is still much stronger for that kind of operation.

Joe

No argument that the shackle is the right choice for trying to free a stuck machine, but a trailer ball is designed to handle quite a bit of horizontal load....and it's not a "rolling load," it's just a load.

If you're at the bottom of a hill, dead stopped at a traffic light, with a 14K pound trailer behind you, there's going to be one heck of a horizontal load on that trailer ball when you start accelerating.

We simply don't have enough details about the incident to have any idea what happened. We don't know what size/rating trailer ball it was, how heavy the dozer was, how badly it was stuck, etc. It could be that the guy tried hooking a truck with a 6K pound trailer ball up to a 15,000lb dozer, and then the driver of the truck tried snatching it out...or some other poor choice.