rotary cutter help

[A Moore]

I recently got a rotary cutter from a friend that needed a pto shaft. I orderd a new pto shaft and used it today. Now the gear must of been too small for my tractor cause it cracked and leaked oil everywhere. If I order a new gear box for the rotary cutter what size should I get? I have a john deere 5065e. Some companys advertise that there cutters cut up to 3 inch trees. If you were to get the right pto shaft and gear box for any cutter would it cut 3 inch trees?

Thanks

 

[HEC]

I am sure some do or try too , but not with my tractor and cutter .

 

[JRobyn]

The frame and other features of the cutter are designed for a PTO HP range which should not be exceeded by the tractor. You'll notice that cutters designed/spec'd to cut heavier growth have heavier gauge steel in the decks, heavier blades, and higher-rated gearboxes (and commensurately higher prices). To replace your broken gearbox, you need to find out what the original HP rating was and duplicate that. Then you'll need to be sure to not exceed the cutter and gearbox ratings with your tractor. Sounds like you might need a lot heavier cutter!

- Jay

 

[jeff9366]

A Rotary Cutter suitable for cutting 3" trees will require at least 75-PTO horsepower from the tractor and will weigh at least 1,700 pounds cantilevered past the rear axle, making the front end light.

Every new RC sold has a horsepower rating for its gearbox. Personally I would want the gearbox rating to be double the PTO horsepower put out by my tractor. When you hit something with the RC the transient load on the gearbox is humongous.

Tractors are not equipment which work long with minimum strength additions.

Brown 672HD Extra Heavy Duty Brush Cutter with 72" Cut | 145 HP @ 540 RPM | Single Tail Wheel | Brown Manufacturing | 800-633-8909

 

[Poopdeck Pappy]

I recently got a rotary cutter from a friend that needed a pto shaft. I orderd a new pto shaft and used it today. Now the gear must of been too small for my tractor cause it cracked and leaked oil everywhere. If I order a new gear box for the rotary cutter what size should I get? I have a john deere 5065e. Some companys advertise that there cutters cut up to 3 inch trees. If you were to get the right pto shaft and gear box for any cutter would it cut 3 inch trees?

Thanks

Did you try to cut a 3" tree with it? Is that why it cracked? What cutter do you have?

As others have said, you need to put the proper size gearbox on for the rotary cutter you have. If you want to cut 3" trees, you may need to buy a heavier duty rotary cutter. But make sure your slip clutch is working correctly, or you have the correct shear pin installed if it's a shear pin model. You could do a lot of damage to your tractor hitting a 3" tree with a cutter that has a slip clutch that's rusted together.

 

[A Moore]

Did you try to cut a 3" tree with it? Is that why it cracked? What cutter do you have?

As others have said, you need to put the proper size gearbox on for the rotary cutter you have. If you want to cut 3" trees, you may need to buy a heavier duty rotary cutter. But make sure your slip clutch is working correctly, or you have the correct shear pin installed if it's a shear pin model. You could do a lot of damage to your tractor hitting a 3" tree with a cutter that has a slip clutch that's rusted together.

I was not cutting 3 inch trees. I cut grass for a half hour to 45 mins then I went to a different field and was cutting grass and thorn bushes. I guess I need to know if I can fix the rc I have and just use it to cut small brush or would it be better to buy a new one.

 

[MinnesotaEric]

FWIW, the 6' Woods BB720X that I have is rated to cut 3" trees, weights 1200 pounds, and uses a 120hp 540 PTO rpm gearbox that is Woods own design.

As you can see, not exactly a small or delicate bit of kit.

 

[mikehaugen]

Unless the cutter is in very good condition, it's many times not worth replacing the gearbox... they aren't cheap.

 

[BethelHntr]

I bought a rebuilt replacement 40 horse gearbox for a older well built hand me down bush hog for $164 + ship from ebay, A lot cheaper than purchasing a new unit.

 

[jeff9366]

What cutter do you have?

You need to put the proper size gearbox on for the rotary cutter you have.

AMoore: Respond completely to the folks devoting their time to help you.

 

[LD1]

Agreed. What cutter do you have? What is the condition? do you have any pictures of it??

All pertinent info for trying to answer the question "is it worth putting a gearbox on"

And its not just as simple as putting a bigger box on it. Biggerboxes usually have bigger output shafts. So that means changing your stump jumper/carrier. Which there is a good chance it may be a slightly different diameter, which would also mean changing the blades as well.

But bottom line, regardless of input horsepower, you you shouldnt have destroyed the gearbox if the slip clutch were adjusted properly, or you had a proper grade shear pin in there. What type do you have?

 

[A Moore]

Agreed. What cutter do you have? What is the condition? do you have any pictures of it??

All pertinent info for trying to answer the question "is it worth putting a gearbox on"

And its not just as simple as putting a bigger box on it. Biggerboxes usually have bigger output shafts. So that means changing your stump jumper/carrier. Which there is a good chance it may be a slightly different diameter, which would also mean changing the blades as well.

But bottom line, regardless of input horsepower, you you shouldnt have destroyed the gearbox if the slip clutch were adjusted properly, or you had a proper grade shear pin in there. What type do you have?

I called my friend and he said he bought it at the local farm store for $800. I pulled out the manual to see what brand it was and all it says is rear mount rotary cutter. I could not find a name anywhere on the unit itself. The steel on the deck looks like it is in good condition.

 

[jeff9366]

That R/C has a spindly frame and mast. It is very light duty. No wonder the original owner improvised additional bracing for the tail wheel.

I would not invest in the repair of this R/C. One part after another will fail. I would buy a heavier constructed R/C, whether new or used.

Tractors are not equipment which work long with minimum strength additions.

 

[LD1]

Yea, that looks like a king kutter. light duty model. Either a 40hp or 60 hp gearbox. I noticed the input shaft is splined. That means it should have a slip clutch on the PTO shaft. Did you get one when you purchased the PTO shaft?

As to fixing it.....

Depends on what you want. if you are always gonna be cutting some dense thick brush, then you need a better cutter.

IF just cutting the same field of pasture grass every few months, it will hold up fine. I think the replacement KK gearboxes are ~$250 for a 40hp one and ~$350 for the 60hp box. Bot you need to know what one you have.

You can also buy aftermarket gearboxes for $100-$200. But you still need a slip clutch. ~$80-$100.

At the end of the day, its still a light duty cutter that is only worth 300-400 in good working used condition. So how much you invest is up to you.

 

[A Moore]

Yea, that looks like a king kutter. light duty model. Either a 40hp or 60 hp gearbox. I noticed the input shaft is splined. That means it should have a slip clutch on the PTO shaft. Did you get one when you purchased the PTO shaft?

As to fixing it.....

Depends on what you want. if you are always gonna be cutting some dense thick brush, then you need a better cutter.

IF just cutting the same field of pasture grass every few months, it will hold up fine. I think the replacement KK gearboxes are ~$250 for a 40hp one and ~$350 for the 60hp box. Bot you need to know what one you have.

You can also buy aftermarket gearboxes for $100-$200. But you still need a slip clutch. ~$80-$100.

At the end of the day, its still a light duty cutter that is only worth 300-400 in good working used condition. So how much you invest is up to you.

I did not get the slip clutchI just used a shear bolt to seer if the cutter would work.