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JD 318 PTO shuts off by itself

pto 318 mower clutch

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#1 hdg4400 OFFLINE  



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Posted October 04, 2015 - 09:26 PM

Good evening:


I'm having trouble with the PTO Clutch on my JD 318. I'll mow fine for 30 -40 minutes and then it will start shutting off all by itself. For awhile I can usually get it to work by turning off and on the PTO switch. Then it will get to a point where I can only start it again by turning off then on the switch and jerking the hydrostatic to forward quickly (sort of like popping the clutch on a car). By the end of mowing it will shut off every 75 - 100 feet.

Occassionally the engine will also die. But when I shut off the PTO switch, it starts right up when I turn the key.

I'm thinking it has something to do with all the safety interlocks, brake/seat/hydrostatic in neutral, but if that's it why would it wait until everything is really warmed up?

Hopefully in the next couple of days I'll get a chance to check all the connections on the safety interlocks and look for any loose or frayed wires.


Any help would be appreciated.

#2 Littledeere OFFLINE  



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Posted October 04, 2015 - 09:44 PM

Sounds like it needs to be adjusted there are 3 nuts with springs under them you put a feeler gauge in the slots

I think it calls for 15th but I have had better results with 13 th


Maybe somebody has some pics to make it simple




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Posted October 04, 2015 - 11:30 PM

I think Little Deere has the right idea, check the air gap. Set it between 14 and 18 thousands, I usually split the dif and. Go for 16.
Also there is a relay near the front crossmember that can vibrate and lose contact you might check.

#4 olcowhand OFFLINE  


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Posted October 04, 2015 - 11:38 PM

The engine sometimes dying sounds like the electromagnet may be shorting out.

#5 Alc ONLINE  



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Posted October 05, 2015 - 05:29 AM

When my 318 PTO clutch needs adjusting as described above . it will turn on fine and hasn't ever disenged   by it's but after 1/2 hour of cutting it won't engage unless jerking the tractor like you do . I would check the wiring and also the voltage at the time it's happening , maybe give you some clues . I wish I had a better memory because when my voltage regulator went bad it  acted up also did some strange things with the PTO on ,

The engine sometimes dying sounds like the electromagnet may be shorting out.            


Come to think of it that might have been the symptoms when the clutch went bad .  

#6 hdg4400 OFFLINE  



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Posted October 25, 2015 - 02:39 PM

Me again.


I went out of town from October 9th thru the 20th, and just getting back to checking it out. When I backed it out of the shed this afternoon and drove it up to the garage to check it out, the tractor died part way up the hill after less than a minute. The PTO was not on, and it started right away, The last time I mowed (probably October 8th, it got real bad, sometimes it only took about 20 feet for the PTO to disengage, and about half the time the engine would also kill. Though I seem to remember that when the engine was dying, it would sometimes come back to life by itself if I shut the PTO switch off quick enough. That made me think it was related to the PTO switch, but now it is dying even when the PTO is off. "Curiouser  and curiouser!"


I bought a set of feeler gauges (good ole harbor Freight) and I'm going out now to check the gaps. Gotta go away in a little while, so will be putting the side panels and putting it away, if it stays running that long.


Update: I was able to check the gaps before going furniture shopping. Looking at the tractor from the front using clock positioning, the gap at 3 o'clock is about .019, at 7 o'clock is about .012 and at 11 o'clock is about .018.


To set them to .016, do I just open/close the gap so the .016 feeler slides in and out with only a little drag, and the .017 feeler won't slide it at all? Sounds right, but haven't done this before.


Again any help or suggestions would be greatly appreciated.



Edited by hdg4400, October 25, 2015 - 04:29 PM.