3320 Forward and Reverse Intermittently Stopping at Higher RPMs

[pmqdflls]

I have a 2011 JD 3320 eHydro with just over 500 hours on it. I've been using it regularly of late to move mulch, bush hog fields, tow a trailer around the yard, etc and no issues. When I went to do some tilling today the forward motion stopped suddenly – forward and reverse pedals did nothing. No strange noises, no drop or spike in RPMs, just no response to either pedal. After confirming I hadn't accidentally bumped into neutral, I shut the tractor off and checked the wiring under the pedals which seemed normal. Once I restarted things seemed to be working again so I assumed there was a loose connection or some debris, until a few minutes later when the same thing happened. What I eventually noticed is that if I throttle down all the way, they begin working again like normal. But as soon as the RPMs get up above 1500 or so, the issue repeats within a few minutes. I checked the oil level and that seems fine and the wires seem okay as well. No error codes have flashed, so I'm somewhat at a loss as to where to begin. Thanks for any advice!

 

[beenthere]

Welcome to TBN

Hope others see your situation and can chime in to get you some help, or ideas to check something out.

 

[Spindifferent]

Questions:
Does the same issue happen in A, B, and C speed ranges, or just in a certain range?
Does the issue happen with Mechanical front wheel drive (MFWD) on or off?
Does the PTO work correctly at low and higher (above 1500) RPM?

 

[pmqdflls]

Questions:
Does the same issue happen in A, B, and C speed ranges, or just in a certain range?
Does the issue happen with Mechanical front wheel drive (MFWD) on or off?
Does the PTO work correctly at low and higher (above 1500) RPM?

Sorry for never replying to this, I somehow didn't see it and came back across my own post when I was searching for solutions (again).

At some point I did diagnostics and the pedal power all seemed normal, despite no forward and reverse. I had the idea that the problem was a clogged hydraulic filter that was getting bogged down and killing power to the pedals. So over the winter I did annual maintenance in addition to some other fixes and replaced the hydraulic fluid and filters. I started using the tractor again a few weeks ago and all seemed fine. I've mostly just been loading wheelbarrows with compost and wood chips, so nothing particularly laborious. But I have driven it back and forth to my folks place which is 1/4 mi away and no issues.

Until today. I was driving it down an access road and it started bucking a bit as forward motion seemed to get cut off and kick back in. I got to where I was going to load compost and after a load or two it was just not moving at all.

To answer your questions:
1. Happens in A, B, and C.
2. Happens with MFWD on and off.
3. I did not engage the PTO, but all other hydraulics seemed fine. Loader, 3ph, etc.

I should also note that no error codes are being thrown, and I didn't notice any obvious signs of issues with the electrical connections. Thanks for any help!

 

[Spindifferent]

A mystery, for sure.

Time for a professional diagnostic at a dealer or service shop.

Best of luck figuring it out. Please let us know what eventually resolves the issue.