6420 Shift Problems

JohnS1970

Member
Recently bought a 6420 with 24 speed Powerquad and electric reverser. Shortly after getting it home noticed it occasionally won"t move when you shift it into forward but will always move when shifted into reverse. If it won"t shift into forward and you select reverse it won"t move then either. Shut it off and restart and then it will move. Seems to act up whether clutch is used or not. I have a general idea how the system works but I don"t have a Tech Manual (yet). Would anybody be able to give me a general idea of the workings of the reverser system and all the switches, solenoids, modules that are involved?
 
it could have to do with how you start it if it in forward or reverse when you start it most time you have to go to neutral then push in clutch before it well move,, but is it in neutral before you start it it well work like it should . best thing is to have it in neutral and park. before you shut it down.
 
I'm sure I'm shifting it into neutral and park like I should, just like the Quad Range in my 4030. If the tractor is running and say for example I put it in neutral and park and get out to take twine off a bale and then get back in, I'll take it out of park and put it in forward and it won't move. Put it in neutral and park, shut it off, restart and shift it will move. It only does this if I shift to forward. It will always move in reverse. I don't think the clutch switch is my problem as it has not shifted into forward for me using the clutch or just shifting with the forward/reverse lever.
 
(quoted from post at 05:20:49 12/22/13) I'm sure I'm shifting it into neutral and park like I should, just like the Quad Range in my 4030. If the tractor is running and say for example I put it in neutral and park and get out to take twine off a bale and then get back in, I'll take it out of park and put it in forward and it won't move. Put it in neutral and park, shut it off, restart and shift it will move. It only does this if I shift to forward. It will always move in reverse. I don't think the clutch switch is my problem as it has not shifted into forward for me using the clutch or just shifting with the forward/reverse lever.


in that case it sound more like your control handle on the forward reverse what i would do is have my local dealer run a diagnostic run on it . that what i do with then newer tractors but even then it can turn out to be a guess i do lot repairs on jd tractors but the new one are getting to be a real challenge with all the electronic on them and that go for all brands my local dealer has always been real helpful to me but i also works a couple years for then and have been a long time customer which also know make a difference
 
I'm suspecting the forward/reverse handle. I likely will bite the bullet and buy the Tech Manuals on CD. Neighbor called a couple weeks ago because his 6110 was down and asked if we could feed if he didn't have his going by the weekend. Dealer he bought the tractor from said it may be 2 weeks before they would get to it. So I don't expect they'd get to mine very soon since I didn't buy it from them. Sounds like the dealer techs just throw parts at it and see what happens. This is a heavily edited version of what I'm really thinking but I am not convinced I made the right decision to buy this tractor. I realize it's 10 years old with only 1800 hrs. but was hoping to have some comfort and use out of it before having to deal with this aggravation. Overly complex for what it needs to be.
 

I believe that transmission is called a PowerReverser isn't it.

They have a seperate controler for the reverser and it is under the seat. Just a big help might be to put the thing in park on a level surface and get under the thing and look for a loose wire ging to the FNR soleniods. I worked on a guys one time that was acting up and a RAT had got under it and chewed on some wires. All the codes were messed up saying that the Shift unit on the steering column was bad. I can't remember where the controler gets the N signal from. You may think this sounds crazy but if the machine is running and it does not have the neutral signal it will go into default and will not move. If it does not go through neutral it will not shift to forward. When you shut it off the default is reset and if it gets the neutral signal first and then the forward everything is ok. You are not getting any warning lights on the dash.
You can use the dash to trouble shoot this stuff. There is a beep mode that will beep every time a switch is activated.
 
The owners manual calls it a PowerQuad Plus. PowerQuad is 4 ranges/16 gears, Plus is 6 ranges/24 gears. Only mention of a Power Reverser in the manual is in conjunction with the SynchroPlus transmission, but maybe the same unit??
I crawled under the tractor yesterday and checked wiring; everything looked okay. Read somewhere while scouring the Net that solenoid continuity should be approx. 12-13 ohms. The solenoids checked out okay. I have a parts manual but the schematic doesn't tell me which solenoid is which. From front to back is it reverse,forward,enable? There are no lights coming on on the dash. I've pulled the following codes out of the dash. According to the chart in the manual they are: 1. ECU or BCU not sending data. 2. Park switch and signal from FNR switch active simultaneously. 3. Faulty trans enable signal.
What exactly do you mean when you say there is a beep mode? A couple of times I've heard a beep but I assumed it was because I selected forward or reverse before taking it out of Park. The only experience I've really had with these newer tractors is my brother-in-laws 6430. If you put it in forward or reverse and then out of Park it would beep and it would say on the screen on the console take it out of Park and then choose your direction.
From what I can see in the owners manual there's a controller for the transmission (Electronic PowerQuad Controller) and a Park Lock Controller. I don't see a controller for the reverser. Does that seem right? Now that I own this tractor and am getting familiar with it I've noticed certain things. One is the steering column has been apart. Another is that the floor mat under the seat appears to be disturbed. So the controllers are under the seat?
 
(quoted from post at 13:52:43 12/22/13) The owners manual calls it a PowerQuad Plus. PowerQuad is 4 ranges/16 gears, Plus is 6 ranges/24 gears. Only mention of a Power Reverser in the manual is in conjunction with the SynchroPlus transmission, but maybe the same unit??
I crawled under the tractor yesterday and checked wiring; everything looked okay. Read somewhere while scouring the Net that solenoid continuity should be approx. 12-13 ohms. The solenoids checked out okay. I have a parts manual but the schematic doesn't tell me which solenoid is which. From front to back is it reverse,forward,enable? There are no lights coming on on the dash. I've pulled the following codes out of the dash. According to the chart in the manual they are: 1. ECU or BCU not sending data. 2. Park switch and signal from FNR switch active simultaneously. 3. Faulty trans enable signal.
What exactly do you mean when you say there is a beep mode? A couple of times I've heard a beep but I assumed it was because I selected forward or reverse before taking it out of Park. The only experience I've really had with these newer tractors is my brother-in-laws 6430. If you put it in forward or reverse and then out of Park it would beep and it would say on the screen on the console take it out of Park and then choose your direction.
From what I can see in the owners manual there's a controller for the transmission (Electronic PowerQuad Controller) and a Park Lock Controller. I don't see a controller for the reverser. Does that seem right? Now that I own this tractor and am getting familiar with it I've noticed certain things. One is the steering column has been apart. Another is that the floor mat under the seat appears to be disturbed. So the controllers are under the seat?

The 6410 were. On a 6410 the BFI was under the right hand console and the other one was under the right hand front step. I used to have a couple of bad ones that the PTO would not work and I kept them around for just this thing. Everything worked good exept the PTO would not turn on. I have service advisor let me check for sure. I think I have the right disks but they may be at work. We are off for the holidays. If you pulled the codes you know how to put the fuse in the right spot or flip the switch thing. It has been a while. Well you should know how to scroll to the codes. Is that address 2 well address 3 or 4 is the beep mode. one works with the engine running and one works with it off.
If the engine is running it would beep every time the tach sensor went by the sensor. Well one of those addresses if you flip any switch it will beep. and that is on and off. brake peddle diff lock any hitch anything electric get off the seat the seat switch should beep when you get up and beep when you sit down. Your problem is the park and FNR active at the same time. It (controller) will not let anything happen (Default probably until a key cycle). The enable solenoid lets the clutch engage. Enable means everything is OK and we are ready to move. With the machine blocked and in neutral, you can use a metal screw driver to see if the solenoid is energizing. It will pull the screw driver onto the end of the valve when energized.
It sounds like your shift quadrant is messed up where it gets the NOT NOT NEUTRAL signal going into rev but gets the NOT NUETRAL going into F. That is the way the logic works. It uses a signal called NOT NEUTRAL.
Clear the codes and see what comes back when it will not move forward. My wife is going to start looking for me pretty soon.
Good luck.
They are a good tractor. Does it have the power brakes. Everybody loved that. People with the 6430 found out that you had to get the really expensive one to have Power brakes.
 
Okay, lots of questions.
When you say BFI, you are talking about the basic infomator?
I can pull the codes but I still don't completely understand pulling the information out of the computer. I assume the service manual is much more comprehensive than the owners manual.
How do I clear the codes? I played around with it the other day but I couldn't clear the codes. Can you do it with the turn signal, flasher, etc. or do you need special equipment to do that?
And maybe this is a dumb question, but just what exactly are the addresses?
So if I understand this correctly, the controller will be looking for a signal from the park switch that it's not in park, a NOT NEUTRAL signal from the shift quadrant that it is either in forward or reverse and then it will energize the enable solenoid which will send oil pressure to the clutch and energize the appropriate forward/reverse solenoid so the tractor will move?
For something else totally unrelated, I noticed that one SCV lever will move rearward but not forward. Yesterday I backed off the locknut on the cable at the bottom of the SCV. I readjusted it and managed to get the lever to move forward but not far enough to get it to enter float. I'm not sure what is going on here. Any ideas? It has the 300 series remotes.
Thanks for all your help. I'm not sure on the brakes I really haven't had much time to drive it. I sure hope you're right that they are a good tractor. At the moment it's a really expensive lawn ornament.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top