Anyone actually flipped a HST CUT pulling from the 3pth?

[Farmer495]

Pulling above the axle doesn't automatically mean you will flip backwards, especially if using a 3pt drawbar.

If you chain directly to the top link mount on the tractor and hook to something solid and have good traction......

Whether it's hydro or gear is doesn't matter, a hydro transmission isn't a magic safety feature aside from the "deadman" aspect of a foot pedal drive.

I've had the front end lift off the ground plowing in good traction pulling BELOW the axle. If the tractor can't move forward and tires can't spin out, tractor will rotate on the axle. Hitching above the axle makes a back flip EASIER to occur.

 

[bcp]

I've had the front end lift off the ground plowing in good traction pulling BELOW the axle.

You can see this in the hundreds of tractor pull videos on the internet. The front wheels rise, then later the rear wheels spin, and forward motion stops.

Bruce

 

[Oldpath05]

Definitely scarry and dangerous stuff. I think that is why It's become recycled dogma on TBN?.. Or I'm wrong about the real risk.

Where on the tractor were you tied off?

Wasn't tied to anything, I just panicked, not much safety features on old tractors, but I think if that old Case was an HST and not on cruse, it wouldn't of flipped

 

[Oldpath05]

I have a hook welded on the top of my boxblade. When pulling from the hook with the 3 point hitch fully raised the tractor spins out before the front lifts. With the loader removed the outcome might be different.

Yup, same idea as when my front end comes up, my pto winch blade hits the ground and the rear tractor wheel spins out.

 

[Snowback]

The key is to make sure that any witness is unable to "witness" anymore... (save for the throngs of additional spectators.)

For the record, I use a 3pt simple drawbar to haul my trailer around in the yard as I can pick it up and set it down easily. If I had to pull stumps, I would use the mounted drawbar below the axle.

 

[Luke'sScreenName]

Of course that's a geared tractor and it more being pulled than doing the pulling. Pretty stupid though.

 

[Snowback]

Of course that's a geared tractor and it more being pulled than doing the pulling. Pretty stupid though.

Yeah - I'm with you Luke. I think it would be nearly impossible to flip an HST machine unless your foot became stuck, cruise was on, or you were trying to win the Russian Roulette tug of war with these Indian guys... Did you see how high they had the chain attached? And the other dude just kept on trucking. Yikes!

 

[CurlyDave]

...Certainly a geared tractor can easily be flipped by pulling from above the rear axle height (i.e. the 3pth). Theoretically a HST equipped tractor can be flipped the same way if you ignored all instincts and didn't take your foot off the pedal...

There is a persistent myth that pulling from below the rear axle is always safe. This is just plain not true. Of course, the lower the attachment point, the less likely a rear flip is, but the real physics of the situation is that the overturn is caused by torque. The real pivot point is the bottom of the rear wheels, and the lever arm is the distance above the ground to the attachment point.

The draw bar attached to the bottom of the differential is engineered so that as the tractor rises in the front the attachment point is lowered in the back and hits the ground well before the tractor rises to a dangerous degree. This reduces the lever arm to zero and the tractor can not overturn.

Sure, it looks like the pivot point is the rear axle, but this is an illusion.

* * * * *

You can pull from wherever you want and the safety police are not going to show up and give you a ticket, but no one will ever catch me pulling that way.

One of the real issues is that the restoring torque to right the tractor is weight of the front end times the distance from the contact point of the rear wheels to the center of mass. As the tractor rises, the angle causes the lever arm to shorten as the cosine of the rise angle. The more it rises, the lower the restoring torque, and the faster things get out of control. This is how people get killed.

 

[swines]

The three point hitch puts the virtual hitch point in front of the tractor when the hitch is used correctly with the top link in the correct hole for the pulling load, the hitch arms lowered, and a three point hitch implement. That's one of the benefits of the three point hitch, it prevents rollover as the rotation point is no longer at the rear axle - it is in front of the tractor.

As you raise the three point hitch, the hitch point moves backwards toward the rear axle, making heavy pulling unsafe with the hitch raised.

A three point hitch should never be used with a single pulling point - that's what the drawbar is for. Using the three point hitch with a single pulling point changes the geometry of the hitch (triangulation of the hitch points) and moves the rotation point toward the rear axle.

Using a three point hitch with it raised and with a single pulling point is dangerous and there is a possibility of rollover as the rotation point is moved close to the rear axle.

 

[4570Man]

Yup, same idea as when my front end comes up, my pto winch blade hits the ground and the rear tractor wheel spins out.

No, the back wheels loose traction before the front wheels lift. With the loader removed this might not be the case. But you're right the box blade would prevent the tractor from going over backwards.