L2800 HST PTO shift lever problem

[Harvest Moon]

So would it be possible to just add a lever and do away with the cable?

I'm pretty sure it's possible, I think it's the same lever on our transmission housing that you'll find on the gear model but ours is actuated by cable because the HST pedal is in the way. There doesn't appear to be an aesthetically convenient or practical place to put one though.

 

[philipb]

All of these ideas have helped, they made me think. I went back to the lever, the cable, and then the boot that surrounds the cable (the boot is less than an inch long). It turns out that the cable sees so much resistance down in its jacket that it just kind of bends in the area that the boot covers. I held the boot between two fingers and moved the lever, the cable straightened out, actuating the cable through the cable jacket, and, evidently, disengaged the pto. Some oil through a siringe is probably needed.

Now, what a pain in the butt. This is bad engineering. It is unsafe. I'll check with Kubota in Ft. Worth about a recall because of the safety issue. I wonder what their solution is. I like the way this machine works but this is one of a few problems that just make no sense to me about it.

Thanks to all for your help. Phil

 

[philipb]

The more that I think about this, the more I think that Kubota has cheapened out on the selection of their cable. A more rigid cable would really help, and, locking down the end that is attached to selector would help in the lever putting a lot more concentrated force on the cable inside the jacket. One of my customers builds custom control cables. I can see a design that is all metal and much more rigid, like a wrapped wire jacket, and a heavier wine inside of it. The cable on there now just kind of flops around.

 

[ccsial]

I've used Honda cable lube (motorcycle product) on mine. I have not yet had trouble at 230 hours. If it sticks I will manufacture a hard lever to operate it. I'm sure it is possible but may take some doing.

One should disengage the PTO at the sme time as pushing in the clutch. Once the mechanism stops rotating it will take more force to disengage.

 

[Marcussen]

All of these ideas have helped, they made me think. I went back to the lever, the cable, and then the boot that surrounds the cable (the boot is less than an inch long). It turns out that the cable sees so much resistance down in its jacket that it just kind of bends in the area that the boot covers. I held the boot between two fingers and moved the lever, the cable straightened out, actuating the cable through the cable jacket, and, evidently, disengaged the pto. Some oil through a siringe is probably needed.

Now, what a pain in the butt. This is bad engineering. It is unsafe. I'll check with Kubota in Ft. Worth about a recall because of the safety issue. I wonder what their solution is. I like the way this machine works but this is one of a few problems that just make no sense to me about it.

Thanks to all for your help. Phil

I agree about what is happening, I looked at both of my failed cable and where it bends the strand flare out and makes it so the cable do not slide correctly, a better quality (stiffer) cable would probably work. I have been thinking about a solid lever but have not come up with a working idea.

 

[Harvest Moon]

One should disengage the PTO at the sme time as pushing in the clutch. Once the mechanism stops rotating it will take more force to disengage.

The leaver on my transmission housing definitely sticks but this is good advice and will probably help. I usually tolerate that horrible ratcheting sound till the end, despite a lot of TBN advice against it, because my manual says to.

My problem is, when the lever sticks I'm often not getting a full disengagement and I fear just catching the lips on the cams with a partial disengagement or delayed release and rounding them off, causing failures like 8226hamer had.

 

[canoetrpr]

I disengage exactly the way ccsial does - disengage the same time as I push the clutch.

I can't see why there would be any problem with this. I lube the cable with silicone lubricant but do have a problem getting it right in the hole.

ccsial - does the honda cable lube come with something special that ensures the lube goes down to the cable.

Kubota has been using cables for PTO disengagement for along time as far as I can tell. A friend of mine has a B7200 whose hour meter broke at 2k+ hours about 5 years ago and it seems to have a cable mechanism as well. He's had zero problems.

So far I am crossing my fingers as I have had next to no problems with my machine at 190 hrs and 3+ years.

 

[ccsial]

Idoes the honda cable lube come with something special that ensures the lube goes down to the cable.

Nothing spedial. It has the plastic tube that most spray lubes come with. I lube from the top in hopes that it runs down hill.

 

[ccsial]

My problem is, when the lever sticks I'm often not getting a full disengagement and I fear just catching the lips on the cams with a partial disengagement or delayed release and rounding them off, causing failures like 8226hamer had.

This is one time I disagree with the manual. When you press the clutch the ratcheting begins. Disengaging the PTO during this time is easy since it is unloaded.

There is a small rake angle on the old style clutches. Once it stops the cable has to overcome this extra friction to disengage.

Besides that, disengaging at the same time as the clutch is pressed reduces the ratcheting which should be less wear.

If I recall correctly 8226hamer had the failure from rototilling. I would not operate a tiller with mine unless I had the new style PTO clutch installed. My suspicion is that the tiller causes chatter on the clutch which tends to destroy it. That痴 just my theory, no proof.

 

[Harvest Moon]

Yeah, I'm on board with the disengage at clutch method now, too many good reasons to ignore the manual on this one. Still not sure why the leaver sticks, maybe I just need to wear it out a little.

I don't discount the tiller theory but mine was always that 8226hamer's problems may have been a result of poor or partial engagement as a result of this prolific cable complication.

It's a tough guess because I can't recall another PTO failure since, lots of people use tillers, lots of people have sticking cables. Maybe he just got a lemon.