Mowing PTO disengaging while in use

   / PTO disengaging while in use #1  

whistling dixie

New member
Joined
May 23, 2011
Messages
7
Location
Central MS
Tractor
Ford 1900
My 1900 pto is disengaging while I bushhog. This problem started a few months ago and only happened once or twice during the time it took to cut 3 acres. Finally, last week the problem progressed to where my boot being lodged on the lever would not even keep it engaged. The previous time cutting my boot being lodged on the lever held it in the engaged position. However, this last time cutting I could feel grinding in my foot through the lever and the pto would stop turning but my boot would still have the lever in the engaged position.
Can anyone tell me what is broken?
Could I fix on my own (I'm a rookie), or would a mechanic have to fix?
Cost?
 
   / PTO disengaging while in use #2  
My 1900 pto is disengaging while I bushhog. This problem started a few months ago and only happened once or twice during the time it took to cut 3 acres. Finally, last week the problem progressed to where my boot being lodged on the lever would not even keep it engaged. The previous time cutting my boot being lodged on the lever held it in the engaged position. However, this last time cutting I could feel grinding in my foot through the lever and the pto would stop turning but my boot would still have the lever in the engaged position.
Can anyone tell me what is broken?
Could I fix on my own (I'm a rookie), or would a mechanic have to fix?

There is a spring and a ball part of a detent mechanism that works in conjunction with shift fork and pto sliding gear. There might be where your problem
lies.You can go to NH website under part to see the illustration with the parts I explained. I can post a pdf of the parts tomorrow. Can you for ever tried to used a bungee cord, a piece of sting or wire to keep the pto lever in engaged position ? if it continue without jumping out I can say most likely is detent mechanism rather than sliding gear issue.

JC,
 
   / PTO disengaging while in use #3  
you might look at the pto diagram that is common to both Ford 1900 and 1700. PTO shifter fork is item #43, ball#44, spring #45 and arm#52. A notch in the arm hold the ball in place with the spring to make it tight and not sliding back and forth like what appears in you description (pto jumping out). The whole assembly #13 is your ORC (Over Running Clutch) or pto one way clutch. The engagement handle can easily be removed and the spring is behind the cover. The spring might be damaged or broken or the ball might be out of round.

JC,
 

Attachments

  • 1900 & 1700 pto arrangment.pdf
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   / PTO disengaging while in use #4  
with machine off.. grab the pto shaft and yank on it.. does it have any in / out movement.. if so.. it will walk a sliding coupler style clutch out of engagement.. chew the ends of the shaft and coupler, and eventually mushroom the internal end of the shaft from thrust play. usualy cause is bad bearing, damaged split ring or bearing carrier ring lands damaged.

that is , if it is not a simply ball and detent problem.

post back.
 
   / PTO disengaging while in use #5  
Hate to say it, but if a foot on the lever won't keep it engaged it's unlikely to be the just detent mechanism. But that's certainly the first thing to check...
 
   / PTO disengaging while in use #6  
any new news?
 
   / PTO disengaging while in use
  • Thread Starter
#7  
Thanks for all the input.
Sound guy, if I yank on the pto shaft it only moves a millimeter or few at most both in and out and up, down, and side to side. It has had this much free play since I've had the machine, which is about a year. I didn't think this was the root of the problem. I figured it was an acceptable amount on a 30 year old machine.
I spoke over the phone with local NH dealership last year when it did it for the first time and explained to them what I told you and didn't get much info just be careful when taking the lever off cause the spring may fall down into the tractor. If this did happen would I be able to get my hand down in there or does the tractor have to be split for thi
 
   / PTO disengaging while in use #8  
Below you see a typical geometry of the detent mechanism. in this case it is for the gear shifter mechanism. The ball can not fall in the transmission unless you take it out and just drop it in there. in the case of the shifter you can lose the spring if you do not withdraw the spring before taking the cover off. It is ball and then spring in a horizontal layout for your pto. Can't see how You can can lose it. No split is necessary or needed. Simply loosen the round cover (#53,54,55) that pto shaft handle goes thru and the the spring is right behind it. Did you look at the diagram I previously posted?

JC,

DSC08085.jpg


DSC08083.jpg


DSC08101.jpg
 
   / PTO disengaging while in use
  • Thread Starter
#9  
JC, your pictures and diagrams should help a lot. Looks like its time for me to get my hands dirty. In the last picture, what do all the springs go to? Are they just extras you have or do they all go in the tractor? What are the 4 things in the bottom of the picture?
Thanks
 
   / PTO disengaging while in use #10  
JC, your pictures and diagrams should help a lot. Looks like its time for me to get my hands dirty. In the last picture, what do all the springs go to? Are they just extras you have or do they all go in the tractor? What are the 4 things in the bottom of the picture?
Thanks

There are for shifter Boss's along with their associated shifter fork and the 4 spindles. Spindles have concave holes with about the same dia of the the steel detent balls. so each spindle /shifter combination gets one ball and one spring and the bolt on top. On mine one of them had 2 spring , one inside another and never figured out why.The original factory diagram don't show that. I reckon it was added by the previous owner to make it a bit stiffer to avoid jumping out. obviously my pics show the transmission but the concept is exactly the same. Do look up at the file I attached a few posts ago. you have one ball and spring for your pto. it is not a difficult job to inspect. can you keep it from jumping by a piece of bailing wire?

JC,
 
 
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