JD 4610 - No Tilt Function on Loader

kcjengr · Jun 24, 2023

So today I let my neighbor use my JD 4610 tractor to pull some junk out of the woods, and for some reason half way through the job the tilt function on the JD 460 loader quit working.
I checked the usual suspects (loose QC fittings, blown hose, hydraulic level), and can not find any obvious issues.

I did notice that there is a huge amount of air in the tilt cylinders, so much so that I can manually push / pull to full extent of travel.
At first I thought maybe a piston seal failed, but if I connect the tilt hydraulic lines to the boom fittings the tilt works fine, and the boom no longer works.

Next I tried disconnecting all the QC fittings and pushing the check valve in with a screwdriver, and I am getting hardly any fluid out of the tilt QC fittings when moving the control valve to the tilt up or down positions. The odd thing is that the engine bogs as if it is building pressure.

Would what cause no fluid to these ports, but everything else on the tractor to work fine?
I am completely stumped at this point, any advice would be appreciated.

Tractor is a JD 4610 with hydro trans, factory fitted hydraulic top link and rear hydraulic ports controlled by the same lever as the loader, with factory diverter to select front or rear control.

Thank you!
Kurt

K5lwq · Jun 24, 2023

Is this a joystick or two separate handles? If a joystick I would suspect the pivot block under the handle boot is broken or has come loose from the curl spool.

kcjengr · Jun 24, 2023

It is a joystick type!
I thought of that, but the pivots appear intact and the engine bogs when the curl spool is moved one direction or the other, so the value appears to be working.
But there is no flow to the QC fittings, which does not makes any sense since its only about 24" of hard line to the QC fittings from the valve.

K5lwq · Jun 24, 2023

What about the rear remotes? Does the loader valve still work both remote functions when you divert flow?

oldnslo · Jun 24, 2023

Kc
With the engine off look at the amount off spool movement you get when moving the joystick for lift lower vs curl dump. I suspect K5 is correct in that something has worked loose on the ball joints for the curl dump have worked loose so spool is moving far enough to start blocking system flow but not allow flow out to the work ports.

Hoss710 · Jun 24, 2023

have you looked under the bottom of the joy stick to see if and branches or sticks are stuck under there ? I had that happen once when my brother in law borrowed my tractor.

kcjengr · Jun 25, 2023

Thanks for all the replies!

I have rechecked the linkages, and the spools seems to be moving fully (based on the mud and rust lines on the spool).

I checked, and there is also no pressure to the rear QC ports corresponding to the tilt lines at the front.
I guess this pretty much narrows the issue down to the SCV or the diverter value.

Reading the manual, I see there is a "regen" function on the SCV when moving the joystick to the far right.
I can't say I have ever knowingly used the regen function...

From the manual

Move the lever right to divert fluid to the red connector line and return through the yellow connector line. Move the lever to the full right or “regen position” to divert fluid and apply pressure to both connector lines

What does it mean by applying pressure to both connector lines?
Could the regen valve be stuck, blocking all flow from the tilt spool?

oldnslo · Jun 25, 2023

Regen is another position of the main spool similar to float on lift lower so would no effect on getting pressure to QD. If diverter is just for this function i would double check to see if it is shifting.

kcjengr · Jun 25, 2023

The diverter looks like it diverts all functions.
I'm not extremely familiar with hydraulics, could the diverter valve get stuck in an in-between position?

oldnslo · Jun 25, 2023

Possible but if diverts all functions the loader would not raise.

K5lwq · Jun 25, 2023

KC, can you post pictures of the loader valve, diverter valve, and the plumbing. I have searched some pictures on line but not real sure how things work on this one.

It appears the loader valve is mounted near the right rear tire with steel lines going to the front of the operators station with quick connects there for a loader.

kcjengr · Jun 25, 2023

I am starting to think it may be the diverter valve that has some how failed..
The manual mentions is has four shift spools, so maybe one got stuck, killing tilt?

oldnslo · Jun 25, 2023

Kc
In reading the theory of operation it sure sounds like one of the diverter spools could hang up causing the problem you experiencing and explain how the other functions could also work properly.

kcjengr · Jun 25, 2023

K5 I will try to get some pictures of the valves, but they are extremely difficult to get to without removing at least the wheel and fender.
I spent several hours laying on my back today trying to see how everything works lol

One thing I don't like about this tractor is how much more difficult it is to work on compared to my Kubota or old Ford.

K5lwq · Jun 25, 2023

Look real close for pulled wires while you are at it. I have a better understanding from the notes you posted. I am now thinking one solenoid valve is not firing. Hopefully just a pulled wire. Being it was working in the woods that is very possible.

kcjengr · Jun 25, 2023

K5, I'm thinking you may be right about a pulled wire!
It appears no power is getting to the diverter switch.
Started tracing it back but a T-storm hit, so will have to wait until after work tomorrow.

Really appreciate all the help!

Torvy · Jun 26, 2023

Hopefully, you will get it figured out. This is why I dislike borrowing or lending mechanical things. Maybe your neighbor misused it, maybe it was about to fail anyway.

As usual, these guys have the troubleshooting well in hand.

kcjengr · Jun 27, 2023

I took this morning off work for a prenatal appointment with my wife, but the midwife got stuck in traffic.
Decided to take advantage of the wait to pull the rear wheel to get better access to the valves (those darn wheels are heavy!!!).

Of course, the carriage bolds holding the fender spin free, and the nuts are rusted in place, so I can't get the fender off...
But at least got better access to the diverter valve.

Here is the general layout, SCV is right behind the joystick, and the diverter valve is what is visible next to the axle.

Here is the diverter.
The hard lines are seized to the nuts, so when I try to remove them the lines twist.
Trying to avoid breaking a line, so I guess I'll leave in place for now.
The four lines on the top closes to us go the the rear QC ports, the ones on the back top go to the SCV.
The lines on the bottom go to the front (loader) QC fittings.

There are four plugs on the back of the valve body, are these what I remove to check for a stuck spool?
I connected a 12v battery to the solenoid, I hear a slight click, but no clunk, which I'd expect from the spools.

Thanks again for the help guys!

kcjengr · Jun 27, 2023

Bad news, midwife still is not here.
Good news, I pulled the solenoid spool and it was stuck!

I got it freed up and now I get some slight clunking from the diverter valve,
and I can divert the boom up/down from the front QC to the rear QC (this was not working before).

So now I think the only remaining problem is a stuck internal spool in the diverter.
Hopefully if I can get that freed will be back in business.

Our son is five days past his due date, he just may be waiting for the tractor to get fixed!