John Deere 3520 No cab 2007 no forward or reverse after hydraulic oil filter change

[Radar72]

Hi all. I hope I can get some help with my 3520 E hydro. I pulled it onto the shop to do the hydraulic oil change and fix a leak. Oil has been changed before but not the filter. I have all JD parts and oil. Drained oil and changed the filter. Removed the suction filter and cleaned it, it was not dirty. Had to remove the rockshaft and replace the o-ring on the shaft as it was split and that is where the leak was. Put everything back together. I have had a TPS error code 8 for the past few years so I thought I would clear it. Did not quite know how but I did some research on Dr. Google. I went into Diag. mode 3 turned calibration to on and just moved the throttle lever up and then back tractor not running. Turned the key off and it went away and never returned. Started the tractor hydraulics work fine, loader and 3 point hitch but it will now not move. No sounds or anything just will not move. No new error codes either. I have checked voltage at the TPS and reset it. 0.9-3.1 volts. Check both the forward and reverse pedal voltages. Both are 0.5 - 3.7 volts. Checked all gear positions A, B and C. Nothing. Seat switch has been bypassed with jumper since new. Did not touch the wiring so cannot see that being the problem. Load match switch is off and so is cruise switch. Tried calibration mode with tractor on axle stands as I have the tech manual. When you put it into calibration mode and it tells you to push FPEDAL you push the pedal and the screen will not change it says FPEDAL forever. will not calibrate. Unhooked the battery and then retried calibration, same thing. Next thing I am going check is the seat harness just in case and possibly the MFWD sensor. I cannot see why changing the oil and filter would stop the machine from moving. Has to be something I did with the console. By the way it just turned 6000 hrs. First time the hydraulic filter was changed. It was my father in-laws tractor before me and he does not believe in annual maintenance. If it was me it would have been change at least 6 times by now. This is why I changed it as I knew it had never been done.
Could the filter be not seated right? It just pulls out and shoves back in. Sorry for the long story but this has me going WTF. Snow is coming.
Thanks for any help. Worst case I am phoning the dealer and see if they can send out a tech.

 

[Radar72]

So I checked power at the seat switch. 12v at red wire. When I put it into Diag. mode 2 it shows the proper readings at the TPS and the pedals so I know it is getting power. I rechecked the fluid level this morning and it is down to just above add. I wonder if there was air in it and it has finally worked its way out. I need to get more oil so I will top it up and see what happens. You would think I would hear something trying to move even if the fluid is low but i hear nothing.
Will try and keep posting updates.

 

[Radar72]

Okay. So I topped up the oil and purged the air according to the tech manual, still nothing. Waiting for tech to call back from dealer.
It has to be something simple.

 

[Radar72]

I see know one is even attempting to comment on this baby. Which is fine. Tech came out last Wednesday Dec 2 and checked out the unit. Went through all the checks and wiring diagrams. Only thing he could figure out is it is a bad controller.
One is on order so we will put it in, calibrate it and see what happens. Wish me luck.

 

[super55]

You are right about changing the fluid only should not have done this and most likely occurred during re-calibration. For some reason it's not recognizing past the first step and is staying forever forward as you said. Usually its the potentiometers that cause the issue. Just out of curiosity do the pedals have adjustable linkage. It almost sounds like when you let off the pedal the tractor is still recognizing fwd signal which is keeping it from allowing you to go to the Rev. step.

 

[Radar72]

You can adjust the sensors on the pedals only which I have done. They are in spec on the high side but the low side is a little low. It says in the tech manual to hold the pedal down until it says Rpedal and not to release it until it does. It never gets past this point.

 

[PCABE5]

I see know one is even attempting to comment on this baby. Which is fine.

You should post this in the owning and operating section. Posting in the ag tractor section won't get you the views or responses.

Most owners will tell you to avoid the calibration mode. Never seems to go well from my understanding.

 

[super55]

I am kind of curious to see if there was a solution as well. You are right the manual recalibration, definitely a multi-step process and it seems when computers don't want to cooperate it doesn't go well.

 

[Radar72]

I am kind of curious to see if there was a solution as well. You are right the manual recalibration, definitely a multi-step process and it seems when computers don't want to cooperate it doesn't go well.

Sorry that I might have posted this in the wrong spot but oh well. We did manage to get it going. A tech came up from the ag. tractor dealer and tried hooking it to his computer without any luck. He adjusted all the sensors to their highest voltage point. The tps was not staying in range. He had to take some play out of lever that went into the back of the sensor. Once he did that we put it into calibration mode and it went through the whole process no problem. I guess the problem was the tps. Voltage was not quite in range. His tech manual was updated and showed higher values. That seemed to work and all is good now.

 

[PCABE5]

Good news that you got it fixed.