When using my bushhog I usually lower the throttle to idle while the PTO is still engaged because that stops the blades faster. I notice when I do this that the engine makes a slight sound similar to when you use an engine brake, except of course there's no engine brake. Is that hurting anything? It's kind of like that barking noise diesels make when they first start up. I'm imagining the inertia of the mower driveline is trying to force the engine to run faster than it wants to given the small amount of fuel being injected with the throttle set at idle.
Mowing Disengage PTO before idling down?
- Thread starter BeezFun
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leonz
Super Member
Disconnect it at speed and then dont worry about it as you are adding load other wise.
It adds wear to the power train where the disconnect allows the implement to slow at its own rate of speed whee the inertia and gravity simply does its job
It adds wear to the power train where the disconnect allows the implement to slow at its own rate of speed whee the inertia and gravity simply does its job
Larry Caldwell
Super Member
I doubt that it makes a difference. Idle down before you engage the PTO.
radman1
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It is best to idle down before shutting of the pto. Why? Because of the pto brake. Every modern day pto has a brake. Safety device to stop the pto faster than just "coasting" to a normal stop. When your coat is being wrapped into the pto shaft and your buddy shuts off the pto, you will be greatful for the pto brake. High speed rpm and lots of pto inertia, put more strain on the pto brake and it will wear out faster. My large ag tractors with pto brake can undergo a lot of braking with 1000 rpm ptos. I can actually push a button on my tractors to override the pto brake and allow the pto to coast to a stop.
Many times when mowing, I will idle down, disengage the pto and keep moving the tractor/mower into uncut grass, to help slow down the pto and prevent more wear on the brake.
Many times when mowing, I will idle down, disengage the pto and keep moving the tractor/mower into uncut grass, to help slow down the pto and prevent more wear on the brake.
radman1
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Forgot to add, the pto brake is why you see the shaft of the pto stop very quickly even without a pto shaft attached. If you ever see a modern tractor take a long time to stop the pto from turning, the pto brake is probably worn out.
RickB
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That is incredibly bad advise if the tractor in question has a PTO brake. Shutting the PTO off at speed while using an implement with a high inertial load will wear the PTO brake exponentially faster than closing the throttle, then disengaging the PTO.
LD1
Epic Contributor
It hasent been metioned yet and I am not sure weather his tractor has one or not, but mine and most others do.....what about the overrunning clutch????
The engine can only drive the PTO, not the other way around. SO if it bushhog wants to run 540 rpm and you Idle the engine down with the PTO still engaged, the engine WILL NOT try to slow the PTO at all. So there is no difference between Idling down and then shutting off, or just disengaging at speed. Either way the brake is the one doing the work. Unless you slow the engine down at about the same speed as the BH would slow down on its own. But that would take forever.
The engine can only drive the PTO, not the other way around. SO if it bushhog wants to run 540 rpm and you Idle the engine down with the PTO still engaged, the engine WILL NOT try to slow the PTO at all. So there is no difference between Idling down and then shutting off, or just disengaging at speed. Either way the brake is the one doing the work. Unless you slow the engine down at about the same speed as the BH would slow down on its own. But that would take forever.
DavidAubke
Silver Member
I assume my little BX2350 does not feature a PTO brake. I was never aware of such a thing and have always disengaged before throttling down. The mower seems to spin down on its own with no assistance from any brake.
Volfandt
Veteran Member
I always reduce rpm before I engage/disengage the pto. As was pointed out, theres a braking assembly involved and by reducing rpm you lessen the wear and tear on all the involved assemblies. As for slowing down to idle I prefer alittle more rpm than idle as it can stall when engageing and lug when disengageing, both of which are bad 
The clicking sounds etc are probably from the slip clutch doing it's designed thing.
Dave
The clicking sounds etc are probably from the slip clutch doing it's designed thing.
Dave
LD1
Epic Contributor
Idling down does NOT help lessen the wear on the brake as others keep mentioning. There is the overrunning clutch preventing the engine from slowing down the implement.
When you Idle down, and the mower or bushhog slows down, it is not due to the motor slowing, it is the brake assembly at work. So it makes NO difference wether you disengage at full RPM, or wether you idle down. There are only 3 things that can slow down the implement
1. The brake
2. Friction and resistance of bearings/gearbox (just slowing down on its own)
3. Having the blades doing work(still trying to cut in tall grass, etc.)
If your tractor does not have an overrunning clutch, this does not apply. But if you didn't have one The inertia of the blades spinning would make the tractor idle down very slowly, and if in gear, will actually try to drive the tractor.
With older tractors such as the N series fords, which didnt have live hydraulics or two stage clutches, it was very easy to be pushed through fence rows and such with a bushhog, unless there was an overrunning clutch adapter.
When you Idle down, and the mower or bushhog slows down, it is not due to the motor slowing, it is the brake assembly at work. So it makes NO difference wether you disengage at full RPM, or wether you idle down. There are only 3 things that can slow down the implement
1. The brake
2. Friction and resistance of bearings/gearbox (just slowing down on its own)
3. Having the blades doing work(still trying to cut in tall grass, etc.)
If your tractor does not have an overrunning clutch, this does not apply. But if you didn't have one The inertia of the blades spinning would make the tractor idle down very slowly, and if in gear, will actually try to drive the tractor.
With older tractors such as the N series fords, which didnt have live hydraulics or two stage clutches, it was very easy to be pushed through fence rows and such with a bushhog, unless there was an overrunning clutch adapter.
radioman
Super Member
pto brake? hmm this is new to me. How would I go about finding out if my BX has them ? I would imagine that the sounds ld1 heard would be simalar to the jake brake effect ecept that the engine valves are not shut off. Perhaps both ?
TripleR
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Well I hate to admit my ignorance, but I have done both, so I guess I am right at least some time though most of the time I disengage at speed. I have a tractor forty years old and one close to thirty.
keyman1808
Platinum Member
I could be wrong but I believe the manual says low RPM or half way to engage and disengage the the PTO. Thats what I do. I forget now. But on my BX24 I engage it at about 1500 RPM the bring it up.
beppington
Elite Member
I have been (without thinking too much about it) "usually" disengaging my PTO at slow PTO speed ... mainly because my dealer told me that starting the PTO at slower engine speed is easier on everything. I was just thinking in reverse.
DiezNutz
Veteran Member
I would offer that before anyone take any advice from this thread, they first understand what type of PTO they have, and whether or not they actually do have a PTO brake.
"One Size Fits All" does not apply here. "Engage at low-to-mid rpm" is the only thing that could be said universally true of all.
"One Size Fits All" does not apply here. "Engage at low-to-mid rpm" is the only thing that could be said universally true of all.
pitt_md
Veteran Member
My MX5000 has the PTO brake but I can't really say if it spins down quicker if you idel down before disengaging or not.
David_Kb7uns
Veteran Member
The Bx tractors have a hydraulic clutch pack. These have several disc sets that get compressed by the hydraulic clutch cylinder. When the Pto is shut down the hydraulic flow is stopped and the clutch cylinder is pushed back by a spring and the brake disc then is compressed against the clutch and thus is braking the Pto.
David Kb7uns
Marcussen
Gold Member
With my HST and the know issues of the L2800/3400 PTO clutch problems I always engage the PTO at low speed and disengage at high speed before going to idle, and I always use the clutch while engaging or disengaging. I about had a heart attack when my Son In law engaged the PTO at high RPM without using the clutch. I don't think these economy tractors have a PTO brake.
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