JD 4610 - No Tilt Function on Loader

kcjengr · Jun 27, 2023

I think the spools probably just got stuck from lack of exercise.
I have never used the rear QC ports, or even switched the switch for the diverter, and I don't have a hydraulic top link.

Talking with my neighbor, it sounds like he bumped it into neutral by accident, and while trying to get it to move again started flipping switches.
I think he hit the switch for the diverter, and it partially diverted, which caused the curl to stop working.

I have pulled and freed up all the spools in the diverter, but still have some issues,
so next I guess I need to figure out how to remove the rusted fasteners and pull the fender to take a look at the SCV.

At least making progress...

These are two of the stuck spools from the diverter.

oldnslo · Jun 27, 2023

Interesting on those valves binding up from lack of use but totally possible since “silting” is a problem in hydraulic valves where there is a small flow path like leakage across a spool filtering out particles (silting up) and eventually causing them to stop working.

kcjengr · Jun 29, 2023

So I'm to the point I need a little more help.
I cut the bolts that help the fender and got it off, exposing the SCV.

Mechanically, everything looks fine, but still no curl.

There are three caps on top of each of the SCV spools, I pulled them off and found a small spring and a little plastic plug underneath.
The plastic plug for the hydraulic link arm and boom valves were free, and easy to pull out.
The plug for the curl is stuck, and I can not get it to wiggle or pull out.
The others were not a tight fit at all, so I am not sure what's holding it in place.

Does anybody know the purpose of these plugs, or if the one being stuck could be the issue?

oldnslo · Jun 29, 2023

Kc
Is the picture with the plastic plug the main lever operated directional valves or the diverter assembly?

If diverter assembly the schematic you posted on Sunday indicated the diverter spools were piloted on one end and spring loaded on the other to default position. The spring chamber also shows being vented to atmosphere. Is it possible those plastic pieces are part of the atmospheric vent? Might connect to drain line into transaxle vs to outside dirty air. No clue how Deere designed this feature.

kcjengr · Jul 4, 2023

Just wonted to follow up on the ultimate issues and fix.

The plastic plunger is the load holding check valve, that is supposed to prevent fluid from back flowing under heavy loading. It is the top hat part shown in the this cutaway.

The plastic plunger had gotten deformed due to extreme overloading and got extruded into the passage it was supposed to seal off. This is the main inlet passage to the spool, which explains why I was not getting any pressure to the curl cylinders.

I had to drill out the remainder of the plunger to open up the passage, which restored the curl function. The check valve no longer functions, but that's a relatively minor loss.

Thanks for all the help!

P.S. Our son was born at home Sunday, strong and healthy! He and I spent much of the day yesterday and today putting the tractor back together while my wife recovers. Not sure how much he learned, but he's probably got more wrenching experience than most other 48hr old babies!