Rotary Cutter Brush Hog gearbox ratio

[Brumm]

You hardly ever see them anymore but I imagine the primary advantage for a ground speed PTO was for a wagon or trailer with a powered axle. A PTO shaft would connect to the tractor and drive the wheels on the trailer. This was a feature for things like forage wagons and would effectively give the operator another driven axle to get though muddy conditions.

In your scenario BRUMM I would be afraid that your MF135 wouldn't have enough horsepower to spin a 6ft cutter in heavy grass at less than full engine speed. My understanding is that engine speed required to hit 540 RPM on the PTO is typically at the peak of the powerband for the engine. While spinning the engine slower with the higher ratio gear box would be more efficient in light cutting applications, if you have heavy grass to cut it may stall out the tractor. I have a slightly smaller tractor I use with a 5 ft. cutter and 2 ft. grass is sometimes more than I can handle if it is very lush.

Thank you for your information and sharing your experience. So I better build a 5' dec. I really wish the 135 had a Perkins 4 cylinder sometimes . Thank you once again for your kind response.

 

[timbatrader]

The ground speed PTO is not good for bush-hog work the momentum of the blades will drive the tractor forward even if you hit the clutch and brakes and back off the throttle to avoid something a scary way to drive. Re ratio change if what you are mowing is not to thick and demanding much power , I like to have the tractor RPM down a bit lower than the RPM needed to have the PTO spinning at 540. The changed ratio will mean you can drive at a quieter more comfortable and economical RPM and still have the blades spinning at the design speed

 

[Brumm]

The ground speed PTO is not good for bush-hog work the momentum of the blades will drive the tractor forward even if you hit the clutch and brakes and back off the throttle to avoid something a scary way to drive. Re ratio change if what you are mowing is not to thick and demanding much power , I like to have the tractor RPM down a bit lower than the RPM needed to have the PTO spinning at 540. The changed ratio will mean you can drive at a quieter more comfortable and economical RPM and still have the blades spinning at the design speed

Yes I agree on the ground speed PTO advice you shared. Regarding the gearbox increased ratio yes its also good for the crankshaft bearing and pistons to use in less acceleration. Affecting positively for the engine lifespan. I heard the modern Massey Ferguson that are made have an less RMP engine to improve maintenance and wear. That's something new I guess as everyone wants fast and powerful equipment with big engines. Thank you for your valuable advice.