sudden and violent PTO engagement with new Kubota MX5800

[boggen]

i can understand why, a simple solenoid on/off only setup with push button to engauge/dis enguage PTO is had. (cheap and simple)

demand for joystick or slider for PTO. with a variable position solenoid. so you can feather it out.

be nice if HST transmission for tires, with a HST PTO. so one could control both speed of tractor, and RPM's of PTO. and let engine auto adjust to demand being placed on it. vs running the engine up to X RPM's for Y PTO RPM's. finishing mowers and cutting short grass to over grown grass, to weeds, to rotatory mowers, fail mowers, tillers, etc.. be nice to adjust lower RPM's for more torque, and vice vs. for the PTO. heck even backhoe's, get higher hydraulic GPM (gallons per minute) at reduce pressure, to have backhoe move faster, adjust HST PTO and get more pressure and slower backhoe movement to get stuff done.

 

[Luke'sScreenName]

FWIW, the only things I have run on my pto are a medium duty shredder and a posthole digger. Always engaged at idle and never felt like a jarring start.

Maybe upload a video (I'd like to see your EA shredder anyway )?

 

[motownbrowne]

This is sort of a band aid fix, but what about engaging the PTO while the mower is in grass. I'm just thinking that the grass might hold the blades away from each other so they don't get tangled up.

 

[bookmyer]

My old Mahindra would shake like crazy with the 4 foot Howse shredder. I thought it was most likely the shredder. I would always engage the PTO at a low RPM as you are supposed to. Seemed that it would shake worse at a higher RPM.

 

[SkylineAcres16]

I have a MX5800 and a heavy-duty bush hog and it has never shut-off while engaging the PTO.

 

[rbtjr]

I have a MX5800 and a heavy-duty bush hog and it has never shut-off while engaging the PTO.

I assume that your MX has the electrically controlled on-off PTO switch. Correct? If so, the variable other than typical tractor-to-tractor variances might be that the EA heavy duty mower has 4" wide blades, while my impression is that most have 3" wide blades. Our MX has shut down three times when I was engaging the PTO to run the mower. The first two times involved crossed-up mower blades. (And BTW, without getting into detail, I don't think our blades are bent.) The third time did not. But on the third time, and for sure on the prior two times, I think that the shut-down was a stall due to sudden overload at the low rpms.

Would you describe the PTO engagement on your MX sudden and pretty violent? If not, how would you describe it with your HD mower?

Thanks.

 

[Steve1300]

With all that has been said, I would quit blaming the mower or the PTO. I'd be looking at a seat switch that is out of adjustment. If it does not have enough over-travel, the shaking may be just enough to shut the engine down. Try tying the switch lever down and see it the machine quits dying on you. Of course, it can be any of the switches that are able to shut the engine off, but that is where I'd start.

Of course, since I am not there to watch it happen, this is only by view from the description.

 

[dnw64]

I assume that your MX has the electrically controlled on-off PTO switch. Correct? If so, the variable other than typical tractor-to-tractor variances might be that the EA heavy duty mower has 4" wide blades, while my impression is that most have 3" wide blades.

One more variable is the engine RPM at PTO engagement. You said you were doing so at idle, he may be doing it a "low" RPM, but more than idle.

 

[boggen]

if there is a load already on the engine. and turning on the PTO at idle.... and with open center hydraulics. i would say disconnect quick connects on hydraulics and re-connect. to see if one of the quick connects not seated correctly. and partially closed causing a load on the engine.

above would be assuming higher RPM's and PTO does not stall engine to point it dies.

other possibility, in high range gear. and go peddle/hst peddle not returning to correct position and causing load on engine.

=========
as others already pointed out seat switch. i can see someone reaching over / moving about. and switch kicking engine off. i want to say i remember a couple folks "light weight folks" not heavy enough to keep seat switch engaged or some such. do not remember full details.

 

[scdeerslayer]

I have not had any PTO issues with my MX5200, and I run a heavy duty mower as well. I engage the PTO at a high idle with the mower at cutting height (I just drove over the spot, I'm pretty sure there's nothing there that the blades are going to hit). I could see that if the back of the mower is higher than the front when lifted then when you engage the PTO that could cause issues with the blade at the back of the mower wanting to swing towards the center before it gets up to speed. I also wonder if the slip clutch is too loose and catching like a bad fishing reel drag. It could just be that the tractor and mower just don't like each other. My grandfather had a sickle bar mower that didn't agree with one of his tractors, making really bad vibrations, but worked fine on other tractors.

If the blades are contacting each other maybe the blade bolts are loose or somehow one of the blades is catching on the bolt when it turns inwards.