John Deere 1435

[Wallystours40]

I have a John Deere 1435 all wheel drive diesel lawnmower. And all of a sudden the self sensing hydraulic control for the mower deck has stopped working. I have tried everything I can think of and talk to the dealers but they say that parts are not available and I can't be fixed. I refuse to believe that if it was made by man it can be fixed by man or different parts and controls put in it. Can anyone help me.

 

[wore out]

I have a John Deere 1435 all wheel drive diesel lawnmower. And all of a sudden the self sensing hydraulic control for the mower deck has stopped working. I have tried everything I can think of and talk to the dealers but they say that parts are not available and I can't be fixed. I refuse to believe that if it was made by man it can be fixed by man or different parts and controls put in it. Can anyone help me.

I have a 1435 WITHOUT the weight transfer option, so I have no direct experience with this.

The weight transfer valve unit appears to be available for $400.91, with no individual parts breakdown.

I have a Tech Manual, I will try to remember to look at it later when I am at the shop and see what info is shown about the weight transfer system.

 

[Wallystours40]

So maybe I'm confusing a weight transfer valve with the automatic rise and lower depending on the train control valve. So my particular mower does not have the weight transfer unit as far as I know it has a control valve that I have had rebuild is specifically for the front mowing deck. It is supposed to automatically raise and lower depending on the train but I'm mowing over issue is that it does not Adam automatically raise and lower anymore I have to do it manually. Which is a pain!

 

[wore out]

So maybe I'm confusing a weight transfer valve with the automatic rise and lower depending on the train control valve. So my particular mower does not have the weight transfer unit as far as I know it has a control valve that I have had rebuild is specifically for the front mowing deck. It is supposed to automatically raise and lower depending on the train but I'm mowing over issue is that it does not Adam automatically raise and lower anymore I have to do it manually. Which is a pain!

I haven't looked at the Tech Manual, yet, however the deck is carried by caster wheels and should be following the terrain.

What, exactly, is the specific issue?

 

[Wallystours40]

This particular mower has some type of sensing unit in the hydraulics that reads the terrain and keeps the deck at a specific level by controlling the lift arms. At least that how it appears to work. I am thinking that weight transfer valve which is located underneath the valve that I already had rebuilt is the culprit It has worked great since I bought the machine but now all of that has stopped. I have not yet been able to find any technical data as to how the system works exactly.

 

[wore out]

I have a John Deere 1435 all wheel drive diesel lawnmower. And all of a sudden the self sensing hydraulic control for the mower deck has stopped working. I have tried everything I can think of and talk to the dealers but they say that parts are not available and I can't be fixed. I refuse to believe that if it was made by man it can be fixed by man or different parts and controls put in it. Can anyone help me.

Here is some info from TM1806.

For the weight transfer system to work the deck lift valve needs to be in the "float" position. Is that how you are operating it/does the "float" position detent in the lift valve work correctly?

 

[Wallystours40]

This is the only control valve that I can find underneath the floorboards and where the controls come down to.

 

[wore out]

View attachment 69828View attachment 69829
This is the only control valve that I can find underneath the floorboards and where the controls come down to.

Did you read the info I posted as to how the system works?

Valve in your photo is the deck lift valve.

https://partscatalog.deere.com/jdrc/sidebyside/equipment/78441/referrer/navigation/pgId/301227092

Do you have the knob, Key #15 that is connected by a control cable to the "weight transfer valve, Key #6?

 

[Wallystours40]

So this is what my helm control looks like. Sitting in the seat as well as a shot from the side. I don't see that control knob that is in the schematic from John Deere. The Black handle lever is the one that I push all the way forward to activate the system. It determines when pushed all the way forward. I am assuming that it activates that valve that I have not found yet. When I get home from work I will dig deeper underneath the hydraulic lift valve and see if I can find it. I guess just follow the linkage.

 

[wore out]

So this is what my helm control looks like. Sitting in the seat as well as a shot from the side. I don't see that control knob that is in the schematic from John Deere. The Black handle lever is the one that I push all the way forward to activate the system. It determines when pushed all the way forward. I am assuming that it activates that valve that I have not found yet. When I get home from work I will dig deeper underneath the hydraulic lift valve and see if I can find it. I guess just follow the linkage.
View attachment 69896View attachment 69897

Apparently you just have the "standard" hydraulics, just like my 1435 WITHOUT the "weight transfer option".

The "fully forward" position of the lift lever is simply "float".

 

[Wallystours40]

You are absolutely right! There is no weight transfer valve of any kind in the system. I found a guy who's partying out the same series lawn machine and has all the parts and is willing to sell them for the weight transfer system. I'm thinking about buying that and installing it in my machine. I'm just wondering why my float system doesn't work anymore. As I think I mentioned before I had a hydraulic repair shop rebuild my valve control call but it has made no difference. I think I may pull it out again and disassemble it myself just to see what's inside it and then rebuild it myself and see what happens.

 

[Wallystours40]

I just read back through our whole conversation and I have to apologize that I didn't pay enough attention when you said. Does your float system detent work correctly? You asked me that a couple of different times. The answer is no it's not working correctly that's why I'll take it apart and see what's inside there. Call it could be that the spool itself or the housing around it is just worn out. But I will find out.

 

[wore out]

I just read back through our whole conversation and I have to apologize that I didn't pay enough attention when you said. Does your float system detent work correctly? You asked me that a couple of different times. The answer is no it's not working correctly that's why I'll take it apart and see what's inside there. Call it could be that the spool itself or the housing around it is just worn out. But I will find out.

Likely you won't have to disassemble much to check out the detent for the float position, it would be in the endcap on the valve that the arrow points to.

I'm not sure if the two hex plugs are for assembly purposes or possibly to adjust the "strength" of the detent.

The parts catalog doesn't show a parts breakdown of the valve, but likely there's some strong little springs and two or three little steel balls in there that will do their best to launch across the shop and get lost! You mentioned it has been previously worked on, maybe the last guy in there didn't recover the launched detent balls!

I'll take another look at the Tech Manual to see if it covers any such details about the valve.

Below is a link to a site that HAD a valve for sale with some up close photos, including of the I.D. tag. A quick search of the Danfoss tag numbers didn't turn up any info or details.

https://www.eastern-triangle.com/john-deere-tca51000-hydraulic-lift-valve-tca20662

 

[Wallystours40]

I am thinking about this. It does not seem like the detent is the problem in that when the lever is pushed forward it clicks into the detent position and stays there. This is the way it has always been and has not changed as far as I know I'm not really sure how adjusting those screws to increase the pressure on the springs will impact. When I checked the screws they were tight so no ability to increase pressure it seems. I took the machine out and ran it and put it in the float position again and again but it does not work. I have no idea what or where the problem could be but some thing has changed somewhere.