L2800HST PTO engagement noise

Boatman

Active member

Equipment
Kubota L2800, Kubota BX1870
Nov 26, 2016
103
26
28
Mill Spring, NC, US
I've been following this just out of interest. Looks like Kubota did away with the overrunning clutch on the new parts. I don't see the need for it with HST - you can still control the tractor speed with the treadle.
By the lack of wear on the lower part of the coupling ramps, I'd say the old one wasn't fully engaging. Probably good you replaced the engagement arm.
This is the reason I am replacing the engagement arm. It would be an easy fix but the part was cheap.
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Boatman

Active member

Equipment
Kubota L2800, Kubota BX1870
Nov 26, 2016
103
26
28
Mill Spring, NC, US
Back to one piece. The only tricky part was getting the spline collar to line up so it would slide together. Did a dry run and tried an couple things along with a bit of wiggling with no luck. Backed it apart and sat there thinking for a couple minutes and came up with using a length of string. Looped it around the collar and tried again. The string allowed me to rotate the little bit needed to get it together. Backed it all off again. Applied sealant all around except for the very top section between the bolts. Got it back to going together, removed the string and applied sealant to the last section. Slid it together the final 1/4" and bolted it up! Easy peasy!

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old and tired

Well-known member

Equipment
L2800 HST
Dec 8, 2019
872
372
63
Raleigh, NC / Hillsville, Va
Cool... I think I can do this... (if and when I need to). Ordered all the parts just to have on hand. I have the same chipper... Bush Hog CS100P but with wearing ear protection, I have no idea if it's skipping or not. I've sold my tiller since it was was skipping so I'm guessing it's just a matter of time before the PTO craps out... It's the Achilles Heel of this tractor!?!

Hindsight, I really wished I had bought these CAMS back when I sold the tiller.... Could have saved some money. Been on my mind about getting them.

Boatman, BIG thanks for posting this, sorry you had to do it.
 

Boatman

Active member

Equipment
Kubota L2800, Kubota BX1870
Nov 26, 2016
103
26
28
Mill Spring, NC, US
Cool... I think I can do this... (if and when I need to). Ordered all the parts just to have on hand. I have the same chipper... Bush Hog CS100P but with wearing ear protection, I have no idea if it's skipping or not. I've sold my tiller since it was was skipping so I'm guessing it's just a matter of time before the PTO craps out... It's the Achilles Heel of this tractor!?!

Hindsight, I really wished I had bought these CAMS back when I sold the tiller.... Could have saved some money. Been on my mind about getting them.

Boatman, BIG thanks for posting this, sorry you had to do it.
I thought the parts were going to be a lot more so I'm "happy". All said and done it cost me about $460. But that included Super UDT2 and Kubota filters. If I wasn't near the fluid change I would have just changed the filters a reused the fluid.

Got it mostly back together tonight..... enough to start it and make sure everything works. Hydraulic system primed fairly fast. I filled it with fluid this morning and it sat all day,,,, maybe it got a chance to somewhat purge itself. As soon as I started the engine I could tell the pump primed. Let it run for a couple minutes to run any air out of the valves and lines. Bucket goes up and down, 3 pt works and machine goes back and forth. Tomorrow I'll finish up with the sheet metal and steps and see how it runs the chipper. Probably wait a couple days before reinstalling the backhoe subframe.
 
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Boatman

Active member

Equipment
Kubota L2800, Kubota BX1870
Nov 26, 2016
103
26
28
Mill Spring, NC, US
Last update.... finally got a chance to hook up the chipper today and I'm very happy with the result. This is the way the pto should work instead of the slipper cams. With the pto engaged and coming down from speed there is no more clacking. Even with the heavy flywheel of the chipper the engine slows right down.
 
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saxon

Member

Equipment
B1550, BX2230, G2160
Sep 29, 2011
46
7
8
Pelzer, SC
Last update.... finally got a chance to hook up the chipper today and I'm very happy with the result. This is the way the pto should work instead of the slipper cams. With the pto engaged and coming down from speed there is no more clacking. Even with the heavy flywheel of the chipper the engine slows right down.


You said "the way the pto should work instead of the slipper cams" Is there more than 1 way to do it???
 

Boatman

Active member

Equipment
Kubota L2800, Kubota BX1870
Nov 26, 2016
103
26
28
Mill Spring, NC, US
Last update.... finally got a chance to hook up the chipper today and I'm very happy with the result. This is the way the pto should work instead of the slipper cams. With the pto engaged and coming down from speed there is no more clacking. Even with the heavy flywheel of the chipper the engine slows right down.


You said "the way the pto should work instead of the slipper cams" Is there more than 1 way to do it???

Look back at post #13 above. The updated cam/clutch is on the left. On the right you can see that the old style is a slipper. If you are running an implement such as a chipper or rotary cutter, when you reduce the engine speed the cams slip and you hear the loud clacking until you either disengage the pto or the implement winds down. With the new style its positive engagement with power on and powering down. This is the way every other tractors pto has worked that I've ever run.
 

saxon

Member

Equipment
B1550, BX2230, G2160
Sep 29, 2011
46
7
8
Pelzer, SC
So what is the root cause of this PTO problem? Is it because the cable was not adjusted properly??
I sure dont want this to happen again at 250-300 hours.
Is it because it has a cable engagment instead of a solid lever engagement?
I think I want a L4400HST
 

old and tired

Well-known member

Equipment
L2800 HST
Dec 8, 2019
872
372
63
Raleigh, NC / Hillsville, Va
So what is the root cause of this PTO problem?...
The root cause, is A) you have to have the ratching Cams only found in the very early models of L2800/L3400 (2004/5 and very early '06).

Looking at your equipment list Saxon; you are fine...

B) you need to be running very demanding PTO implements; normally these failures have been seen on Tillers - this is the first I heard about it from a Chipper (I have the same model chipper) Pretty sure a stump grinder would be out of the question for these CAMS.
 

Boatman

Active member

Equipment
Kubota L2800, Kubota BX1870
Nov 26, 2016
103
26
28
Mill Spring, NC, US
So what is the root cause of this PTO problem? Is it because the cable was not adjusted properly??
I sure dont want this to happen again at 250-300 hours.
Is it because it has a cable engagment instead of a solid lever engagement?
I think I want a L4400HST

I can't really say what the exact cause of failure was in my case. But those original cams have a 90deg engagement face. The front cam is only held in engagement by the spring pressure and it's not a very robust spring. One slip leads to another and it's a slippery slope. Also I believe allowing the cams to slip while winding down may cause the edge to get slightly rounded over. The new cams (not really cams) have a positive engagement angle so the more the rotational force the more engagement pressure.

Like old and tired said,,,, it's been taken care of by Kubota in subsequent models.
 

saxon

Member

Equipment
B1550, BX2230, G2160
Sep 29, 2011
46
7
8
Pelzer, SC
I bought my L3800HST in Oct. 2012. What "cams" would it have?
I need to edit my equipment list to the L3800HST and a B1550HST.
Could the trouble be caused by the linkge cable not being set just right for engagement of the PTO?
I do run a 5' rotary tiller on my 3800 but the tractor ought to handle that easily, even if it is a load on the tractor. Since Ive had the tractor a lot of times the PTO would not disengage when I moved the PTO handle to OFF. A lot of times I had to spray WD-40 on the mechanism where the cable goes, located under the seat.
This is very disturbing to me and I have lost some faith in this tractor. Would the lever engagement style be better than the cable engagement style on the PTO? Would either way still have the vulnerable 'cams'?
 

Boatman

Active member

Equipment
Kubota L2800, Kubota BX1870
Nov 26, 2016
103
26
28
Mill Spring, NC, US
I bought my L3800HST in Oct. 2012. What "cams" would it have?
I need to edit my equipment list to the L3800HST and a B1550HST.
Could the trouble be caused by the linkge cable not being set just right for engagement of the PTO?
I do run a 5' rotary tiller on my 3800 but the tractor ought to handle that easily, even if it is a load on the tractor. Since Ive had the tractor a lot of times the PTO would not disengage when I moved the PTO handle to OFF. A lot of times I had to spray WD-40 on the mechanism where the cable goes, located under the seat.
This is very disturbing to me and I have lost some faith in this tractor. Would the lever engagement style be better than the cable engagement style on the PTO? Would either way still have the vulnerable 'cams'?

Here is the service bull8but I see it doesn't include the 3800 for some reason.

Maybe its was updated with your model.

When you cut the throttle with the pto still engaged ( brush hog attached) is there a loud ratcheting or clacking sound.

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Boatman

Active member

Equipment
Kubota L2800, Kubota BX1870
Nov 26, 2016
103
26
28
Mill Spring, NC, US
NOT even close to having any problems... relax!

Despite my join date - been on these boards since 2005 and nothing outside of the early versions of the L2800/L3400 had this problem. And only maybe a handful of them (55k -ish units?) had the problem and reported it here....
I think he may be concerned because I suggested it in his other thread. I didn't know at the time that the 3800 wasn't an issue.
 

saxon

Member

Equipment
B1550, BX2230, G2160
Sep 29, 2011
46
7
8
Pelzer, SC
I dont have any thing attched to the tractor PTO now.
What about the difference between a cable vs. a lever for engagement?
 

old and tired

Well-known member

Equipment
L2800 HST
Dec 8, 2019
872
372
63
Raleigh, NC / Hillsville, Va
What about the difference between a cable vs. a lever for engagement?
The cable is used on the HST models because the Treadle pedal, pushed in reverse is exactly where the manual PTO lever would be.

The manual lever is more of a positive engagement... but the cable is more in an "ergonomic" position. (my fat ass doesn't have to bend over...)

I'm a little surprised that the manual (gear) tractors didn't also have the cable, just for simplicity. I think they could have done a manual lever for the PTO on the HST but it would have been tightly packed in the corner (and also possibly confusing).

I like the cable for pto, last thing I would want is an electric pto, either on or off.
 
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Boatman

Active member

Equipment
Kubota L2800, Kubota BX1870
Nov 26, 2016
103
26
28
Mill Spring, NC, US
I dont have any thing attched to the tractor PTO now.
What about the difference between a cable vs. a lever for engagement?

I pretty much agree with old and tired's post. Unless the engagement is out of adjustment, either method should be fine. When I broke my cable earlier last year I rigged up a temporary lever until the new cable arrived.
 
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