Strange PTO behavior.

   / Strange PTO behavior. #1  

N80

Super Member
Joined
Aug 2, 2005
Messages
6,909
Location
SC
Tractor
Kubota L4400 4wd w/LA 703 FEL
Maybe it isn't so strange but I'm not sure what happened. I was mowing a few days ago with my L4400 and JD LX-6 mower. I was hot and tired and had to get off the tractor to limb up some pines along the road I was mowing. It was going to take a while so I turned the motor off but forgot to disengage the PTO. Well, it just started spinning down as you'd expect but when I realized I'd forgotten to disengage it, I reflexively reached over and pulled the lever to the off position and it just slammed to a halt. The rpms of the mower had already gone way down but it still made a bang. Once I got back on and engaged it again it worked just fine so I don't think I hurt anything.

I just don't understand what happened. Is there something that locks the PTO when the tractor is off? When the motor was off but the PTO was engaged it continued to free-wheel but disengage it stopped it cold.
 
   / Strange PTO behavior. #2  
Humm I use the clutch a lot with my PTO. Might be the trucker in me, All my levers move better when I clutch, not sure how your tractor works but I don’t fight anything, if it doesn’t move easy use the clutch
 
   / Strange PTO behavior.
  • Thread Starter
#3  
This tractor has a live independant PTO so it should be independant of the clutch. Beyond that, I don't know too much about the mechanics of it.
 
   / Strange PTO behavior. #4  
N80 said:
I just don't understand what happened. Is there something that locks the PTO when the tractor is off? When the motor was off but the PTO was engaged it continued to free-wheel but disengage it stopped it cold.

Motor off, no power. Blades had already slowed down, so no power plus already slowed baldes = stop.
Bob
 
   / Strange PTO behavior. #5  
yea mostlikey the blades was turning the motor.
 
   / Strange PTO behavior. #6  
chucko said:
yea mostlikey the blades was turning the motor.

I doubt that, the tractor would be rocking and rolling is the tail was wagging the dog. :) I can't say what happened but I have done this many times. I know this because if I stop the motor while the pto is still turning it'll make a ticking noise (maybe the overspin clutch, I think it has something like that), I'll reach over and disengauge the pto and the ticking will stop but the mower will still turn. I have a gear tractor like you.

Wait, just re read, you say live pto? if you push the clutch in the pto does not stop? I've only seen that on older or larger tractors.
 
   / Strange PTO behavior.
  • Thread Starter
#7  
The PTO is listed as "hydraulic, live-independant. And yes, it keeps turning whether the clutch is engaged or not. But I'm still confused, I don't understand what slammed it to a stop unless there is something that locks the PTO when it is disengaged via the PTO lever. To review, this is the series of events:

Clutch in.
Stop forward motion.
Turn engine off at key.
(At this point tractor is motionless, engine off, mower blades and PTO shaft spinning down)
Pull PTO lever to disengage.
Bang! PTO and mower blades slam to a stop.
 
   / Strange PTO behavior. #8  
N80 said:
Clutch in.
Stop forward motion.
Turn engine off at key.
(At this point tractor is motionless, engine off, mower blades and PTO shaft spinning down)
Pull PTO lever to disengage.
Bang! PTO and mower blades slam to a stop.

Add, turn engine speed to idle, lift 3 ph to get rotary mower off of ground and grass, (<- anything that might put drag on the blades), let blades come to slow idle speed with PTO engaged, disengage PTO and see what happens.
Bob
 
   / Strange PTO behavior. #9  
N80 said:
The PTO is listed as "hydraulic, live-independant. And yes, it keeps turning whether the clutch is engaged or not. But I'm still confused, I don't understand what slammed it to a stop unless there is something that locks the PTO when it is disengaged via the PTO lever. To review, this is the series of events:

Clutch in.
Stop forward motion.
Turn engine off at key.
(At this point tractor is motionless, engine off, mower blades and PTO shaft spinning down)
Pull PTO lever to disengage.
Bang! PTO and mower blades slam to a stop.

Well sounds like mine is different. If I'm mowing in gear, hit the clutch, everything stops.

Good Luck,
Rob
 
   / Strange PTO behavior. #10  
Doesn't the PTO have a wet brake? When you disengage the PTO the brake slows the implement down so it doesn't free wheel.

I'm guessing that when you disengaged the PTO the brake engaged and brought your already slower spinning blades to a screeching halt.

Just my .02 cents.
Jeff
 

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