JD 425 won't stop moving when forward pedal released

[billmuis]

My JD 425 used to stop instantly when I removed my foot from the forward pedal. It has recently started to continue to move forward, albeit at a slower rate, but it does not stop positively like it used to.
Any ideas as to what to look for would be greatly appreciated.

 

[johnrex62]

Sounds like the pedal is no longer centered properly. It is not releasing it's pressure on the valve fully so it keeps moving. I don't know anything about your machine, and have only had to deal with this type of issue on my Scotts lawnmower, but it was easy to fix on the Scotts by adjusting a threaded rod. Check your manual or do some internet searches if you don't get someone here to jump in with the step by step.

 

[beenthere]

:welcome:

There is a damper on that linkage (like a shock absorber) and there is also a spring in the tranny that may (or may not) be involved.
I'd first remove the seat and the rear fender deck to clean out the top of the tranny, and visually look the linkage over for any restrictions. There can be a lot of dirt and debris buildup under that fender deck. Not a big problem to remove it.

The linkage can be visuallized on jdparts (free registration involved) and that may help you a lot.

 

[kimodc]

I have recently had the same problem. It is not an issue with the pedals not being centered. There is an eccentric neutral adjustment stud on the the side of the transmission that takes care of that problem. I readjusted mine and it is not the problem. I also took the damper off and cleaned all linkages and this did not help either. Mine will stop just fine if I am REVERSING and then take my foot off the pedal, it is just after depressing FORWARD and releasing that it seems to "roll on" further then it should. JD says it should stop within 4-8' after releasing the pedal, and I know mine rolls way past that. I have also noticed that with the throttle full up, it does not roll quite as far, but seems to have a little more braking action.
I don't know what the problem is, but it has me confused as well!

 

[beenthere]

Does the forward pedal hang up and not return to 'stop' position and is in synch with the forward motion? There is one rod that goes from the forward/reverse pedals back to the transaxle tranny, so it is either in forward/reverse or stop. Something must be keeping it from returning. Maybe it is the torsional damper #16. Maybe it is the spring inside the tranny #9 that keeps the swash plate #6 from returning to 'stop' or neutral. Hopefully it is something external. Hard to see what is happening unless the fender deck comes off for observation.

Here is what the linkage inside and outside the tranny looks like.

 

[kimodc]

The linkages seem to work fine, and the pedal is not getting hung up either. Almost feels like something internal, especially since full throttle will seem to stop it a little sooner

 

[beenthere]

I'd be sure the hyd oil and filter were recently changed. Might be expensive if something internal around that swash plate.

 

[Snoxracer]

If you have adjusted the neutral adjustment cam, and nothing else seems to be a problem with linkages etc, I would almost bet it is the sping inside the transmission that returns the shuttle valve to center.

Just my thoughts,

Dustin

 

[kimodc]

I did change the oil and filter, again with no change. I am leaning towards perhaps the spring inside the transmission, but I wanted to read throuh the repair manual first to see if they have any suggestions as to what it might be, problem is trying to read the repair manual online is frustrating to me so I am putting it off. I guess I am old fashioned and like to sit down and still flip through pages.

 

[beenthere]

Here is the diagnosis line in the repair manual that may help... like testing with damper disconnected. This may lead to the need to go inside for the return spring replacement.