PTO HP vs Gearbox HP Rating

[Black Crow Singing]

Looking at a tractor with a rated PTO HP of 55. The bush hog I'm looking at has a gearbox rating of 65hp. So mathematically my tractor is below the bush hog gearbox rating. But I'm wondering if I'm "cutting it too close" in regard to the PTO hp being so close to the maximum gearbox rating on the rotary cutter. Thoughts?

 

[jyoutz]

Looking at a tractor with a rated PTO HP of 55. The bush hog I'm looking at has a gearbox rating of 65hp. So mathematically my tractor is below the bush hog gearbox rating. But I'm wondering if I'm "cutting it too close" in regard to the PTO hp being so close to the maximum gearbox rating on the rotary cutter. Thoughts?

I’m using a cutter with a 45 hp gearbox, but my tractor pto is 52hp. The dealer told me there would be no problem as long as I wasn’t trying to push the limits of the cutter by cutting heavy continuous brush at WOT. I mostly cut grass with some small shrubs and less than 2” saplings so I haven’t had an issue.

 

[sea2summit]

Looking at a tractor with a rated PTO HP of 55. The bush hog I'm looking at has a gearbox rating of 65hp. So mathematically my tractor is below the bush hog gearbox rating. But I'm wondering if I'm "cutting it too close" in regard to the PTO hp being so close to the maximum gearbox rating on the rotary cutter. Thoughts?

That's nearly 20% below the rated HP, totally fine, especially in something like a brush hog where it's not 'really' doing work like a tiller or PHD.

 

[LD1]

ITs not so much the tractor to be concerned with....but what you are cutting.

You can cut pasture grass with a 90hp tractor and a 65hp gearbox all day long and never have issues.

You can also destroy a 65hp gearbox with only 30pto HP if you try and cut 3-4" tree saplings all day long

 

[Sawyer Rob]

That's nearly 20% below the rated HP, totally fine, especially in something like a brush hog where it's not 'really' doing work like a tiller or PHD.

I've never had a PHD work my tractor much at all, even at a little over idle the governor barely kicks in, BUT a rotary cutter in heavy grass will give a tractor a real workout.

As for a tiller, it all depends on soil conditions, it can be easy on a tractor or hard.

What kills most rotary cutters is hitting trash, like big rocks or limbs, and yeaaa I know about sheer bolts and inline slip clutches.

SR

 

[oosik]

If you have the correct shear bolt or the slip clutch is set properly - there should be no problem.

Like SR said - you don't want to be hitting big rocks, limbs or other HARD objects. Do a FOD walk thru the area you will be cutting BEFORE you cut. Keep a sharp eye up ahead - the first time you cut.

Tall grass - cut it high the first time. Makes it easier to see any "bad stuff" before you hit it the second time around - on the final cut.