Brush Hog set-up with a TC35A. Slip Clutch?

[boatyard]

I am going to borrow a 72 inch Brush Hog from a neighbor who has only run much older tractors. His new tractor is a Ford from the 1970's. He said you will need a slip clutch to keep the tractor from continuing to move the tractor forward when the clutch is engaged to change gear or direction.

The tractor is a 12 speed shuttle shift. Is this true for this tractor? Do I need a slip clutch? Any other words of wisdom for my first shot at brush hogging?
Christopher

 

[RobertN]

The over-running clutch is built in to most tractors that I know of these days. I know my TC40 has it, as did my previous Kubota(1985 vintage).

The older tractor had the PTO go directly to the transmission. Didn't help to put the clutch in. If you put a rotary mower one one, like say a Ford 9N, It would drive them till the mower finally stopped. My Dad bought an over-running clutch for his 9N; it was not very expensive.

A TC35 is new enough it should have it built in though.

 

[RickB]

The over-running clutch is built in to most tractors that I know of these days. I know my TC40 has it, as did my previous Kubota(1985 vintage).

The older tractor had the PTO go directly to the transmission. Didn't help to put the clutch in. If you put a rotary mower one one, like say a Ford 9N, It would drive them till the mower finally stopped. My Dad bought an over-running clutch for his 9N; it was not very expensive.

A TC35 is new enough it should have it built in though.

TC35's, 40's and 45's have independent PTO and absolutely do not have a built in ORC. With independent PTO, there is no need for an ORC, as it is impossible for inertial rotation of the implement to be transferred to the transmission output. The original poster's neighbor is confusing an ORC with a slip clutch which has a totally different function. This thread is absolutely chock full of bad info and supposition.

 

[RobertN]

I assumed it was similar to my old Kubota.

How/what does the PTO drive off of?

Enlighten me; now I am curious about how this thing works(really, not joking or being smart-allek).

So mine is HST. I would guess that the PTO drive must be on the pump side of the HST, since pto speed is independent of ground speed.

A slip clutch is used instead of a shear bolt right? My auger has a shear bolt.

TC35's, 40's and 45's have independent PTO and absolutely do not have a built in ORC. With independent PTO, there is no need for an ORC, as it is impossible for inertial rotation of the implement to be transferred to the transmission output. The original poster's neighbor is confusing an ORC with a slip clutch which has a totally different function. This thread is absolutely chock full of bad info and supposition.

 

[boatyard]

TC35's, 40's and 45's have independent PTO and absolutely do not have a built in ORC. With independent PTO, there is no need for an ORC, as it is impossible for inertial rotation of the implement to be transferred to the transmission output. The original poster's neighbor is confusing an ORC with a slip clutch which has a totally different function. This thread is absolutely chock full of bad info and supposition.

I should have been clear from the beginning, I was clueless about running a brush hog on my TC35A, until you started to fill me in. Good information, keep it coming.

So do I need a slip clutch? Or with the brush hog have sheer pins? OR?

Christopher

 

[jinman]

Wow! Let's see if we can handle this without adding more confusion or making anyone feel bad about asking a question. The OP needs some help and I'll try to help him use some correct terminolgy.

1. An ORC is an OverRunning Clutch. They are essentially a ratchet mechanism that slips in one direction and holds in the other direction. Why they were ever call a "clutch" is beyond me. That fact has led to people confusing them with a safety clutch that slips when a cutter blade hits a stump or rock. A safety slip clutch keeps the cutter's gearbox or tractor gearbox from shattering. If there is no clutch, almost all cutters will use a soft shearbolt that will break instead of gearboxes.

2. The TC35A has a PTO that is engaged by an internal clutch inside the tractor. That clutch is engaged with hydraulic pressure when the PTO lever on the left side console is moved to the engage position. Yes...thats yet another clutch to add to the confusion. Because the PTO is independent, it will not drive the wheels through the transmission. As a matter of fact, the TC35A has a brake that stops the PTO from spinning when the clutch is disengaged. It takes only a few seconds to stop the PTO. This brings a cutter to a stop very quickly and provides safe operation. A tractor equipped with an ORC may allow the PTO to spin for a full minute after disengaging the PTO or stepping on the clutch. This WILL NOT happen with the TC35A unless something is broken.

3. The PTO being independent means it will operate anytime the engine is running and the lever is moved to engage. It doesn't care whether the transmission clutch is pressed or not. That's why it is called independent. There is a shaft that is driven directly by the engine that goes all the way through the transmission and straight to the hydraulic PTO clutch.

4. The cutter you are borrowing at 72" has a lot of centrifugal force when running and takes a considerable amount of torque to start up. The best way to operate it on the TC35A is to slowly move the PTO engage while the engine is running around 1000 rpm. When the cutter spins up, then make sure the lever is all the way to engage and then increase the engine rpm to mow. When you get ready to stop the cutter, lower the engine rpm first to 1000 and then disengage the PTO lever. You can disengage the lever at full speed, but this puts a lot of wear on the PTO brake. The brake will last much longer if you lower the engine speed before moving the PTO lever to off.

The upshot of all this is that you can safely use the 6' cutter on your TC35A without an ORC. Your tractor is a modern tractor that doesn't need an ORC, but use your PTO carefully to make it last a long time.:thumbsup:

 

[boatyard]

Wow! Maybe the best reason to own a New Holland tractor.

Owning a New Holland tractor will get you good clear, well written advice from Jinman every time on TBN. And with a smile.

Thank you very much! Christopher

 

[RobertN]

Ok. So I noticed that when I drop the rpm with the New Holland, the rotary mower respond very quickly. Is this because even with the pto engaged, it is still primarily linked to the engine?

I'm trying to envision how this works, and where it actually drives from. From the description, it's operation is independant from the drive system, wether HST or gear type tractor.

On my Kubota, the mower would spin forever even with the PTO engaged, just idled down. From what I could gather from the manuals, it had an internal ORC.

I have heard of independant PTO, but never really thought about the operation.

Cool stuff

 

[jinman]

Christopher, I'm glad I can help you understand a bit about your PTO. It's unfortunate that we don't have any easy way of understanding the mechanics of our tractors because understanding makes operation a lot easier. There are many more things to consider about that rotary cutter you are borrowing. You'll have to make sure the length of the PTO shaft between the tractor's PTO and the cutter's gearbox is acceptable. You want to make sure it is long enough so that the two pieces do not separate, but short enough to allow you to lift the cutter with your 3PH without the shaft bottoming out and jamming the tractor. These are the problems that using a cutter on two different tractors can cause. Because your friend's tractor used an ORC, that makes the driveline shorter overall to allow for the length of the ORC. I don't think you will have a problem, but you need to check it out thoroughly before starting to use the cutter.

I'm also including an illustration of your PTO driveline on your tractor. It talks about the PTO shaft going through the transmission, but what you may miss in this diagram is that the PTO shaft is really a shaft within a shaft, concentric shafts. That's what allows the PTO shaft to be driven by the engine when the transmission shaft is not turning because the clutch is depressed. When the clutch is engaged, both shafts turn at the same rpm.

The diagram and brief description is attached.

RobertN: I'm not including the diagram of the HST transmission because I don't want to add confusion to this thread. I'll post another thread or talk about the HST later if you'd like, but for now I'd like to get Christopher completely clear before doing that.

 

[JC-jetro]

Jim explained it perfectly well, his explanation and a cut sheet where it shows the transmission diagram, relationship of two input shafts to both PTO and transmission mechanism is all it takes to understanding it short of memorizing it.
The bad part is different manufacturer mix the terms and use it interchangeability where it causes the confusion. JD 5000 series is a live, double clutch system but they call it "independent PTO" due to the manner it engages or disengages.

JC,