Hydraulics jerky on Deere 4610

[KWRB]

So I've used this forum for SEVERAL years, relying on others having had similar experiences and the wealth of knowledge shared by members. Class acts, all of you.

Well I registered and came out of the shadows because for the first time ever (save flat tires and a dead battery), my deere 4610 is down. I put it away a week ago with no issues and today this. I'm very concerned. Okay, I'm actually freaking out. Any help would be appreciated tremendously!

Symptoms:
Hydraulics are jerky both in the hydrostatic drive and the loader.

Troubleshooting Completed:
Jerking occurs regardless of direction (forward or reverse) - eliminates pedals as root cause
Jerking occurs regardless of "gear" (A, B, or C) - not a gear
Jerking occurs when raising the loader as well - not transmission, definitely in the hydraulic pumping system
No jerking lowering loader

Work Completed:
Drained approximately ten gallons hydraulic fluid from transmission sump. System contains 9.7 gallons, so it doesn't look like I had a slow leak and was low. Color is dark green looking, I think, but it's in dirty old 5 gal opaque buckets
Removed hydraulic filter and power steering filter. Saved them in case I decide to open them up. Removed the strainer from the sump. Stopped there. I don't want to drop all the money on new filters and fluid, if it's likely a hydraulic pump failure. I also don't want to start tearing into the tractor to get to the pump if it's likely not the pump.

Observations/Conclusions:
Not much. First, the strainer has a substantial amount of metal shavings in it. I'm not certain what to make of it. I have read on here today that if the system's never been opened up, that shouldn't be a shock. I bought this tractor "used" with 120 hours on it, and it has about 400 now.


Questions:
1) Based on the symptoms, does anyone have any general suspicions about the root cause?
2) What is the best way to open up the filter to evaluate without getting saw cuttings in there?
3) Are those metal shavings in the strainer truly not a concern? In my professional experience with a different type of machine, metal shavings mean certain death.
4) Are there truly equivalent alternatives to Deere hydraulic filters and Deere low viscosity HyGard hydraulic fluid? I don't want to cut corners with substandard materials, but I am not a fan of the green paint markup. Also, there is only one company that owns every Deere dealership in Central New York and they jack you with an additional "captive audience" markup that is absolutely infuriating. I have used Fram Tough Guard oil filters, Napa Gold air filters, and Shell Rotella motor oil in the past.
5) What is the likelihood that I have a hydraulic pump failure? If so, how much surgery is needed to extract the pump and to rebuild it?
6) Deere shows two hydraulic pumps in their online parts lists. Are there two hydraulic pumps or is mine one of those two options?
7) Deere's online parts list shows, for the power steering filter, that I should use part LVA10419, but to use LVU14258 when using the 72" mid-mount mower (which I do). I assume this is a shorter filter that doesn't interfere when the mower is lifted entirely. Can someone confirm? Ironically, I know the mower was sold with the tractor when new, and it had the LVA10419 filter on it, with a minor indentation on the bottom that I cannot confirm is from the mower without hooking it all back up.

Thank You all for any help -partial or complete- you can provide

Kurt

 

[Kyle_in_Tex]

I'm not sure how dis-similar my 4310 is, it has a yanmar/hydrostatic tranny. I had a jumpy forward reverse issue with the motion match IIRC. There are 2 hall effect sensors on mine. They can give erratic info to the electronic system that controls the hydrostatic.

You might be able to find a WIX cross referencing your filters. After 400 hours, if you change them, it won't be wasted money.

 

[Kyle_in_Tex]

PS, glad you signed up after all these years. I would love to have a nice 4610/4710.

Keep us posted on the progress/diagnosis. (Your turn to contribute to this wonderful board).

 

[Wagtail]

G'day (again) KWRB.

Look, I know full well that you want to save money on filters. Same thing for the engine oil. That's fine and those things are fairly generic for a Yanmar donk; I've always grabbed the fuel & oil filters from my local 'auto parts' shop, along with compatible oil.

That being said, you've stated that you're at the 400hr mark. According to my Owners Manual, that's the recommended time to change the hydraulic fluid and filter anyway... I know this as I'm at that point myself with my rig. Personally, I'm not going to screw around with something as important as my hydraulic/transmission system by trying to get 'generic' stuff. I've gone to my JD Dealership and bought the JD hydraulic filter and HyGard fluid.

As to "green paint markup" (or, I would suppose any colour paint/OEM markup) it's all a matter of Your Mileage May Vary [YMMV]... For me, the difference really is negligible for the generic stuff. For the important stuff, I'll pay top dollar.

 

[KWRB]

Where are these hall effect sensors located, on yours? I could start digging around in the part diagrams.

 

[Kyle_in_Tex]

One is at the rear of the engine on the side and it reads the flywheel, and IIRC the other is on the output shaft of the MFWD underneath the tractor. They give codes on the flashing code light if they are bad.

 

[k0ua]

I don't know anything specific to John Deere tractors, but a couple of things. I would not be too concerned by that amount of metal in that strainer at 120 hours. And generally when a tractor has jerky hydraulics the first thing I think of is air being sucked into the hydraulic suction side. Through a leaky hose or fitting. Again I am saying in general terms this is what I would suspect and this is not John Deere specific, as I have no knowledge of their history or systems. The L3400 series of Kubota tractors are notorious for a certain hydraulic suction hose that if it develops a crack in it will suck in air to the hydraulic pump and starve the pump from sucking fluid from the "tank". These symptoms is what you would expect. I know a Kubota is not a Deere, but it could be something similar. Or not.

 

[Wagtail]

James, the OP bought the tractor @ 120 hours... he's up to 400 hours now. My manual says to change the hydraulic fluid & filter at that time, which will be the first time for the change.

Other than that, you're correct; a leaky hose or fitting could be causing the fault.

 

[KWRB]

So if I had a suction side leak, I would look from the pump suction fitting to where?

 

[k0ua]

So if I had a suction side leak, I would look from the pump suction fitting to where?

back to the "tank" The transmission of the tractor where approximately 10 gallons of fluid is stored when not being used to extend the cylinders. Of course this operates your hydrostatic transmission also. Usually a section of the hydraulic pump also serves as the "charge pump" of the hydrostatic transmission. This circuit is usually about 250 psi and provides makup fluid for the internal losses.
again this is general info not JD info.