hello and damage without one-way clutch

[Moulin]

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.

 

[BubbaJr]

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

Joe

 

[Moulin]

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

Joe

What I was hoping to hear, thanks!! Means I can go out and cut the grass without worrying

 

[CobyRupert]

Probably only a problem if the attachments had a high momentum (high inertia) weight as compared to tractor's weight/rolling resistance.
Finish mowers and rotavators probably aren't that much inertia as your tests results showed.

...your test was at full operating rpm's right?

As Bubba alludes, if your tractor interlocks even allow attempting a start with PTO on, your starter motor would be doing a lot of additional work turning implement over too. -Edit: I don't think this is true, unless you're starting it in gear.

 

[WranglerX]

Could manual be alluding to use a PTO "Slip Clutch" as opposed to shear bolt?...

Dale

 

[LouNY]

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.

 

[Moulin]

CobyRupert - thanks for clarifying, and yes, was tested at full operating RPM.

LouNY. hmm, bit confused now! It is not an independent PTO. But also not a live PTO - my understanding is that uses a 2 stage clutch to engage (or have I got that wrong?). Mine is just a simple transmission PTO, engaged with the clutch. Are you now saying I should in this case use an overrun coupler? If so, I would appreciate it if you could help me understand why. Many thanks.

 

[Tx Jim]

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.

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.

 

[Scook222]

If you have a transmission driven pto than is powered by a single clutch without an over run coupler when you clutch the tractor while the pto is engaged on a piece of equipment and the tractor is in a forward gear, the tractor will keep moving until the pto stops. If this is the case, I would put an over run clutch on the pto shaft. If it doesn’t move forward it has a built in over run clutch that keeps the tractor from moving forward. On both of the types, you have to push the clutch in to put the pto in gear or it will grind gears. The bigger the implement, the more momentum it will have. The rotovator would be the best to test this out with since the finishing mower should be less momentum. Either way I’m sure you will enjoy your tractor.

 

[finn1]

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.

There痴 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.