hello and damage without one-way clutch

[Molalla1]

In the immortal words of Clint Eastwood, Do you feel lucky?

I don稚, and if the manufacturer recommends an overrunning clutch I wouldn稚 be a cheapskate and not follow that recommendation to save a few bucks.

Thereç—´ a reason that farming and forestry are consistently ranked at the top of the list of dangerous occupations. Powerful machinery, and daily opportunities to take unnecessary risk.

Yep . . . better to error on the safe side.

 

[LouNY]

Sorry Lou but what you stated is incorrect. On a live pto the pto shaft the pto shaft operation is not associated with the traction clutch IE it has it's own clutch so therefore doesn't require an over-running clutch.

""On the other hand a trans driven pto powered by traction clutch needs an OR clutch on certain implements that have flywheel type momentum such as a rotary mower.""

There are 2 different types of live pto 1 style has a dual stage clutch with 2(two) clutch plates which 1 plate is for traction & other plate is for pto. Other type is ind pto with a dedicated clutch with control lever for pto which is normally hyd actuated.

Some JD tractors built by Yanmar have an OR clutch from the factory but I have not a clue about OP's model Yanmar.

If your dual stage is adjusted correctly and kept in adjustment you are correct I have not seen many that stayed in adjustment when worked even with the two stage an over running clutch is a good safety device to protect your tractor, heck I have considered it on a couple of our independent ptos to save the pto brakes.

 

[Texasmark]

If you make it a practice to disengage the PTO before shutting off the tractor, you won't have any issues.

Joe

If you cut the throttle such that the PTO is running faster than the proportional engine speed it will put positive pressure on the gear train and you may or may not....usually the latter may not be able to get the PTO to disengage until the PTO has stopped. On ground speed with the same speed relationship, pushing in the clutch has no bearing as it disconnects the engine from the transmission which is what is driving the PTO in a Tranny PTO power train and the Kinetic energy stored in the rotating blade will continue to propel the tractor in the direction in which it was moving until that energy is exhausted as work...pushing the tractor forward and winding down.

Yes the proper term is Over Run Clutch. Yes you need to have one if you have a Transmission driven PTO and yes you can tear up things without it. Ebay has them for a great price.

My 2016 Branson 2400 has it built in. You can tell if yours is built in by putting the tractor in gear and PTO lever engaged with the engine off, with a pair of channel lock type adjustable pliers or a pipe wrench, grasp the PTO shaft and see you can rotate it in either CW or CCW. If it will rotate one direction and not the other, under these conditions, then you have it internally and don't need one externally.

 

[rangerfredbob]

An inline overrun coupler is $40-60, I went for a few years without one but ran into a couple trees and fences and dug some holes while mowing in mud... I don't think I got stuck once after I got the over run coupler...

 

[Texasmark]

An inline overrun coupler is $40-60, I went for a few years without one but ran into a couple trees and fences and dug some holes while mowing in mud... I don't think I got stuck once after I got the over run coupler...

I just checked ebay as my $45 free shipping one came without the pin (which I fabricated from a bolt) to lock it to the tractor's PTO shaft WHICH HAS TO HAVE A HOLE IN IT TO ACCEPT THE LOCKING PIN. If your PTO shaft doesn't have a hole in it, you have no way to lock it to the shaft. Also

Also ensure that you get a 1 ⅜ to 1 ⅜ unless you have an old tractor like an N Ford or TE/TO Massey which use 1 ⅛ pto shafts whereby the female part of the OC would have to be smaller.

 

[rangerfredbob]

for the record I got THIS ONE that is the quick release version, it works just fine, I didn't want to use the pin type since it would be a pain to go back to pull implements with my tractor's setup...

 

[RickB]

If your tractor has a "live" pto instead of an independent pto you should be using an over running coupler or clutch.
With a live pto your pto is started and stopped using your tractors normal clutch, after you engage the pto.
With an independent pto you can start and stop your pto with a separate lever and your foot clutch will have no effect on it.

Transmission PTO configurations benefit from the use of an ORC. Live and independent PTO drives do not.

 

[LouNY]

If you are using something with a high rotating mass an independent PTO can certainly benefit from an over running clutch.
If you burn out the brake on an independent PTO and price or replace it yourself you will see the benefit.
The main problem is finding one with enough hp rating.

 

[rScotty]

Firstly, I have just joined this forum, so hello!

I have bought a second hand Yanmar Ke-160, which is my first tractor (and first time I have driven one since a Ferguson TE20 as a young boy!).
It came with a FEL, rotavator, finish mower and transport box. I have a lot to learn and am reading through this great forum, but I do have an immediate question.

The manual says it has no one-way clutch, and for high speed tools such as mowers, the PTO drive shaft should be fitted with a one-way clutch (I think this is referred to on the site as an overrun clutch or coupling). The previous owner did not use one of these. I understand it can cause difficulties stopping the tractor when the clutch is engaged, but the shaft only seems to rotate very briefly after doing this (and it does not continue to drive the tractor), and after testing I do not see any risk of it hurtling me through a fence. However, I would like to know if this practice could be doing any damage to the transmission? If it is, I guess the answer is to buy an overrun coupling and shorten the drive shaft?

Thank you.

Most PTO drive shafts are telescoping. If yours is not, then replacing it with one that is would allow you to easily add an over-running clutch. There is no downside to an over-running clutch. With a small mower - not much rotating mass - the downside without the over-running clutch is not so much hurling you through a fence , it is what the momentum of the mower might do to the internals of the PTO as all that torque tries unsuccessfully to hurl the tractor.
.
By far a more common problem is what happens when the mower hits a stump and abruptly stops spinning. Your protection for that is either a "SLIP CLUTCH" or a "SHEAR BOLT". Make sure that part of your mowing system has the right parts and is ready to do its job.
rScotty

 

[RickB]

If you are using something with a high rotating mass an independent PTO can certainly benefit from an over running clutch.
If you burn out the brake on an independent PTO and price or replace it yourself you will see the benefit.
The main problem is finding one with enough hp rating.

Which is not at all what your first comment describes. Live PTO systems seldom have brakes. Many independents do. I’ve changed my share of brake bands and pawls in my time, one in a new to me Ford 4000 and a bunch more for customers.