PTO--does on/off hurt engine

AppleMan · Apr 19, 2009

Does shutting the pto on and off hurt the tractor's engine? I have to shut it off on about half of my turns at my orchard (ground is severely uneven in these spots) and didn't know if it would hurt the engine. In three hours of spraying I probably turn it on and off about 20 times.

5030tinkerer · Apr 19, 2009

I can't imagine how it could. Perhaps there are internal clutches that are getting worn or something (I would think this would be tractor dependent), but that would be about it. If you are only shutting down the PTO when turning around, why not leave it engaged and save the worry?

Duffster · Apr 19, 2009

There would be more risk of damage letting it on from the vibration in the turn

The only thing you could hurt turning it on and off would be the PTO clutch and I wouldn't worry about that

5030tinkerer · Apr 19, 2009

Can you tell me what is meant by vibration in the turn?

Duffster · Apr 19, 2009

5030tinkerer said:
Can you tell me what is meant by vibration in the turn?

Sorry, I guess I assumed the OP was talking about a rear PTO shaft in which in a sharp turn the U-joints produces a vibration

Soundguy · Apr 20, 2009

I think I'd save my pto clutches and invest in a CV style rear pto shaft!

soundguy

jinman · Apr 20, 2009

AppleMan said:
In three hours of spraying I probably turn it on and off about 20 times.

If you were running a rotary cutter or finish mower, I'd say you should not cycle the PTO ON/OFF. However, if you are running a PTO pump for a sprayer, it probably does not have anymore starting torque than a posthole digger. That would probably not put a lot of stress on the PTO clutch or the tractor's engine. So my answer is that if there is little torque required, go ahead. If there is a high torque requirement, then raising the 3PH in the turns might be the best option.

AppleMan · Apr 20, 2009

Thanks much. It is a trailer mounted (not 3pt hitch mounted) in which the pto powers the pump for the sprayer so I'll keep shutting it off on the sketchy turns.

Altex · Apr 21, 2009

AppleMan said:
Does shutting the pto on and off hurt the tractor's engine? I have to shut it off on about half of my turns at my orchard (ground is severely uneven in these spots) and didn't know if it would hurt the engine. In three hours of spraying I probably turn it on and off about 20 times.

Just checking, but are you using your Clutch to dis-engage (and engage) your PTO on and off? You need to with Transmission Driven PTO (not with Independent PTO).

Not using your clutch is the only thing I can think of that would hurt your engine by jamming it on or off. Don't mean to talk down to you, just checking.

AppleMan · Apr 21, 2009

There's no clutch on my model. It's a hydrostatic transmission.

Soundguy · Apr 21, 2009

Any chance of mounting the pump to the pto stucb on the tractor and 'hoseing' it back to the trailer? in effect.. get rid of the pto shaft and u-joints?

soundguy

Ray2210 · Apr 21, 2009

With my 2210 the manual states that the engine should be throttled back when the pto switch is turned on or off. I always do. It really isn't a big deal to do it either I just have to remember. Occasionally I forget when turning it off but really isn't going to be when parts get broken.

dangerdoc · Apr 21, 2009

AppleMan said:
Does shutting the pto on and off hurt the tractor's engine? I have to shut it off on about half of my turns at my orchard (ground is severely uneven in these spots) and didn't know if it would hurt the engine. In three hours of spraying I probably turn it on and off about 20 times.

If you hear the engine lug down when you engage the PTO, I would imagine that there is some excess wear. If there is not enough resistance to to strain the engine when it is turned on, I wouldn't worry too much.

I would worry more about a rotary cutter where you are spinning up a significan mass than with a spray pump.

Duffster · Apr 21, 2009

AppleMan said:
There's no clutch on my model. It's a hydrostatic transmission.

Don't you still have a PTO clutch then?

Altex · Apr 21, 2009

AppleMan said:
There's no clutch on my model. It's a hydrostatic transmission.

Ok, just saw specs for your model that has Independent PTO. Shouldn't hurt the engine turning PTO off and on.

Fyi - Some tractors with HST use a clutch to change between Low, Mid-range and High Gears and at the same time it also has a dual function of engaging/disengaging the PTO.

Soundguy · Apr 21, 2009

Altex said:
Ok, just saw specs for your model that has Independent PTO. Shouldn't hurt the engine turning PTO off and on.

Fyi - Some tractors with HST use a clutch to change between Low, Mid-range and High Gears and at the same time it also has a dual function of engaging/disengaging the PTO.

Even if it had a clutch.. I wouldn't have viewed it as 'hurting the engine'.. rather as wearing the clutch material .

soundguy

dangerdoc · Apr 21, 2009

Duffster said:
Don't you still have a PTO clutch then?

I don't know if it is related, I have a Kubota deisel ZTR mower that is hydrostatic. They recommend putting the engine at idle before engaging the PTO.

Van Wen · Apr 21, 2009

I use a Rears airblast sprayer, a trailer type also. It has an electrically activated fan clutch that lugs the engine when engaging. The manual says to engage at low rpm.

AppleMan · Apr 21, 2009

I should have clarified. I do rev down before I shut it off. Thanks for the heads up that your sprayer manual says the same thing. I just wasn't sure because it doesn't address multiple shutdowns.