John Deere SyncroVantage Power Reverser - Reverser won't work

[JasG]

I have a friend with a Deere 6605 and it has the Syncro Vantage Power Reverser transmission. This is a 16 gear unit that can be reversed in any gear. The reverser lever acts like the tractor is in park when in gear. By that I mean trying to move the reverser lever forward or backwards it wants to stay in N. I checked the linkage on the parking linkage and it seem to be good and so does the gear selector linkages. The tractor will roll when out of park, and shifts fine. Yet the reverser doesn't want to move to forward or reverse. If you push on the lever hard it will engage and tractor will move forward, but nothing in reverse and it wants to return to N on it's own. I didn't try that, but the owner told me that is how he was able to move the tractor out of the way.

It sat for a week or so, but showed no signs of issues when it was last moved.

I am not sure where the linkage for the reverser goes once it enters the dash or how it is tied to the park. When working normally if you forget to put the lever in N before shifting to park it will go to N on it's own. I just don't know how that linkage works or where it is or how it is tied to the parking linkage.

Anyone have this issue and what is the repair?

 

[beenthere]

Might help to look at the parts for linkage on this model..

https://partscatalog.deere.com/jdrc/

Put the model # in and browse for the tractor and tranny your friend has.. or the one you are using.

 

[Zebrafive]

I would start with the park cable and see if it adjusted right. Maybe take it out of park then disconnect the cable at the right side of the transmission?
I have a 6415 with left hand reverser and if it's not in neutral, when I shift the range lever to park, it move the reverser lever to neutral, so they are linked.

 

[JasG]

Might help to look at the parts for linkage on this model..

https://partscatalog.deere.com/jdrc/

Put the model # in and browse for the tractor and tranny your friend has.. or the one you are using.

1st place I went was deere.com. Since they have changed the system, some things are easier, others much harder. I am not able to find anything that ties the park lock to the reverser. Found the gear shift, park cables, reverser cables etc, sections of the transmission. I can't seem to find the connection between the 2.

 

[Zebrafive]

Check these drawings. Link 11 connects the two levers the cables for Reverser and Park lock connect to.

 

[JasG]

Check these drawings. Link 11 connects the two levers the cables for Reverser and Park lock connect to.

I did see those drawings, but wasn't sure. Hard to tell which cable ends up where the way they have it broken down and they don't label things like they used to.
I will go check on this, thank you for the help.


The deere parts look up isn't what it used to be, I think this last change is a huge step backwards.

 

[beenthere]

JasG
Agree "not what it used to be".. but what it "was" is what we were more comfortable with. Hard to change.. but it is now what it is.. for better or worse.

May be that it is better for those responsible for keeping it updated where-as the older version was not so good. Who knows?

 

[JasG]

Check these drawings. Link 11 connects the two levers the cables for Reverser and Park lock connect to.

I had this straight in my head earlier and then looking at your drawings I went with what you had said. I just went and looked at it and that isn't how it is, but these drawings are a pain to use. The drawings they have and the lack of information under the parts name sucks. I used to be able to find issues pretty quickly with the old system. Same guy had issues with the syncro transmission on his 4020 a few times over the years and I could easily figure it out.

That rod (number11) doesn't connect the two at all. That rod linkage connects the parking gear cable to the parking pawl cam and rod, it connects to number 15. The reverser linkage on the side of the transmission is directly below the the lever the parking cable connects to. There is no physical link on the outside between the 2 that I see except the springs (number 10) that help pull it to N when you shift to park. Yet when you take it out of park, the springs do move and the reverser lever on the side of the transmission should be able to move and it won't.

Which leads me to believe it might be something inside the transmission. The shaft that the lever is mounted to that has both the parking cable and that linkage seems to be turning, but nothing is releasing the reverser. I was under the tractor and couldn't get it to move at all by hand.

It's hard because not only do they not label things any more, the drawings should show both cables, but they only show one. The exploded views are hard to follow.

Thank you for taking the time to try to help.

 

[Zebrafive]

Does lever key 10 connect to the reverser cable?

It looks like lever 10 is on shaft 22. Then on the left side, shaft 22 has a link, parts 23-28. I think this link goes to the reverser control valve.
Maybe disconnect the link and see if reverser lever moves shaft 22.
If that moves, see if the control valve it connects to moves. If it will not move, Maybe problem is in the control valve?

 

[jd110]

Sounds like you have some binding linkage or a cable. I would start by disconnecting linkage from the reverser valve assembly under front of transmission. With linkage unhooked, see if lever on valve moves freely by hand. If so, then move back to rear of that linkage. It connects to a lever / shaft assembly that goes through transmission to the other side. Disconnect linkage on other side and see if that shaft going through transmission turns freely. I have seen a few of these bind in this area. If it is stiff to turn, you need to spray penetrating oil on both sides and keep working it until it frees up. If everything there is free. then most likely the cable is tight and needs replaced or the reverser shift lever itself is binding or has worn parts.