On my BX2370 the pto engage lever has always been "touchy". I can move it as slowly as possible and still it will grab all of a sudden. Yesterday just to try it with the mmm, I tried engaging it fast and slow (at reduced engine rpm's always). It doesn't make a bit of difference how fast or slow I move the lever. It's always been that way, just thought I'd bring it up to the experts here. I realize the manual says to move it slowly to engage, it's just that the way mine acts, there seems to be no reason to go slow.
PTO engagement
- Thread starter BotaLoda
- Start date
Kubota's PTO drive is via wet clutch so engagement is dependent on lockup pressure (which is adjustable) btw. Having said that, not going to tell you where the adjustment is because you need to have an authorized dealer set the actuation pressure.
Too little and the pack slips and wears out and too much and lockup is abrupt.
Too little and the pack slips and wears out and too much and lockup is abrupt.
Yes but that doesn't address my question. On mine it makes no difference how fast or how slow I move the lever. I can move it an 1/8" at a time and when it grabs, it grabs with very little slippage. There is no in between area, it's engaged or disengaged. Flipping the lever fast does the same thing as going slow. There is a slight pause before it engages (.5 seconds?), but on is on and off is off. There is no way if I tried to engage it too slowly that I could control a slower engagement of the clutches. Which I understand would wear them, but the point again being that the manual says to move the lever slowly, but it makes no difference how fast or how slow I engage it.
I sure did. Lockup is entirely predicated on hydraulic pressure on the pack and that is controlled by the actuation valve. The cable from the PTO lever just actuates the valve. The valve sets the actuation pressure. Don't matter how fast or slow you move the lever, the valve is controlling t and it needs to be set by an authorized dealer with the proper tools and gauges.
IOW, don't fiddle with it.
IOW, don't fiddle with it.
The reason why the manual says move it slowly is when you have a PTO powered implement hooked to the PTO, there will be some lockup slippage. With nothing on the PTO shaft there is nothing. It's designed that way to mitigate shock loading the implement.
How it works.
How it works.
I'm not planning on fiddling with it! I just wanted to know how it worked. So from what you are saying, were the manual states:
"To avoid damage to PTO clutch and implement, shift the PTO clutch lever slowly, when engaging the PTO clutch."
So those instructions mean nothing because there is NO WAY to engage the clutches at a different rate by how fast you move the lever?
I'm getting de jay vue, did we go through this before?
"To avoid damage to PTO clutch and implement, shift the PTO clutch lever slowly, when engaging the PTO clutch."
So those instructions mean nothing because there is NO WAY to engage the clutches at a different rate by how fast you move the lever?
I'm getting de jay vue, did we go through this before?
OK, so then something is wrong with mine. When I engage the PTO with the mmm attached, there is no way for me to engage it faster or slower. The speed of the lever makes no difference. Once it engages it slows the engine down a bit and blows black smoke for a second. There is no way to engage it any slower no matter how slow I move the lever.
Perfectly normal operation. The wet pack is doing exactly what it's designed to do.
My big tractors do the same thing when I engage the pto. I always engage just above an idle and they both blow a little smoke.
You are looking for an issue that don't exist.
Again, the lever has no bearing on how fast or slow the pack locks up. That is controlled by the proportioning valve.
If you think it's an issue, have an authorized dealer check the lock up pressure and adjust accordingly but it takes special tools and is not something you can fiddle with, which is why I won't tell you where it is. Fiddling with it can cause premature pack failure. The lock up pressure is very specific. If the pack fails it entails splitting the tractor to access it.
Now if you had a WSM you'd know where the valve is and what the pressure needs to be but it still takes special tools to read and set it.
The inertia of getting any implement moving is going to cause the engine to slow down and blow some smoke, unless you have a Tier 4 final engine, in that case the 'smoke (particulates) wind up in the DPF instead, to get roasted during a regen cycle.
North Idaho Wolfman
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It's working fine, that's just the way the BX's are, there is no slow to it, and as you stated it's either on or off.
There is no proportional adjustment on the BX PTO Valve, the speed of engagement can not be adjusted.
The "engage the PTO slowly" is just a carried over term from older mechanical engaged systems.
First, I'm not trying to be argumentative, I'm just trying to find out if in the manual where it says "To avoid damage to PTO clutch and implement, shift the PTO clutch lever slowly, when engaging the PTO clutch." means absolutely nothing. It doesn't need to be there. Right?
Yes thank you very much! That line in the manual does not apply to my tractor. I will now stop *trying* to engage the pto slowly, I will just slow the rpm's like I have been doing and move that lever at any speed I feel like.
Whew! Didn't mean to come off as an @$$ or and idiot, was just trying to get that straight.
I don't really know. Mine say the same thing. I engage my pto's on my tractors the same on all of them, take the lever out of the detent and move it forward. Never think about it, never have.
Sometimes fast, sometimes slow, again, I don't anticipate it. The pack and the modulation valve always controls pack lock up, not you nor the lever.
Lots of stuff in the owners manual and WSM I find not relevant. I just gloss over them. Remember. the manuals are written by some Japanese person and translated into English.
Sometimes fast, sometimes slow, again, I don't anticipate it. The pack and the modulation valve always controls pack lock up, not you nor the lever.
Lots of stuff in the owners manual and WSM I find not relevant. I just gloss over them. Remember. the manuals are written by some Japanese person and translated into English.
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I’m guessing Kubota designed the PTO clutch this way to minimize slippage and ware on the clutch.
I engage the MMM at 1600 rpms, then throttle up. It will engage at lower RPM without stalling, but I don’t like to run it less than 1600.
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I engage the MMM at 1600 rpms, then throttle up. It will engage at lower RPM without stalling, but I don’t like to run it less than 1600.
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Russell King
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The manual may be trying to say something more like “engage PTO lever with engine slow to avoid damage to implement or tractor “.
Technical translation is difficult.
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Technical translation is difficult.
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That is a mistake on your part sir. You should always engage the PTO as close to an idle as possible (without stalling the engine). Engaging the pto at speed (any speed above the minimum), causes undue wear (not ware) on the clutch pack and it will fail prematurely. Keep in mind the rebuilding the clutch pack entails splitting the tractor. Always engage at the lowest possible RPM.
The manual states to go from full throttle down to half speed to engage the pto. IDK, does anyone normally run at full throttle?
SidecarFlip, you might be more familiar with bigger machines. The kubota super mini diesel motor series in the bx18xx and bx23xx idle fast, 1350-1400, cracked off idle is about 1550-1600 where it starts to run smooth, below that is no load range.
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I've owned little ones as well. I'm on my 11th Kubota. Started out with a B7100 and kept getting bigger as my needs got bigger. In retrospect, should have kept the B7100, was a great lawn mower tractor. Bought every one new except the last M I just bought which was used. Always good trade in value and I never had a single issue with any of them except for one defective loader cylinder which was promptly replaced by my dealer.
I'll never run anything but Kubota tractors and I live and farm in JD land.
I take it you have the 2 cylinder diesel, not the 3 cylinder? Looked at one that was in the shop at my dealer's the other day.
Just be aware that the faster the engine is turning the more slip the pack has to do and the more wear takes place in the pack. It's a wet pack so the fluid cushions the plates but like a wet clutch in a motorcycle, they do eventually wear out.
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I just come in from mowing with a 5' Woods brush mower. I watch to see what RPM's did when I engaged the PTO. At 1220 RPM, letting up the clutch easily, the engine never strained a bit, moved the RPM to 532 and mowed. L4240.