Sanity Check -- 3rd Function Build on a Mahindra 4540

[NCFarmLife]

Looking into building a 3rd Function for my Mahindra 4540. Preface - as of two days ago I had no idea what a 3rd function was and had never done any work on my hydraulic system - so go easy on me... Based on ridiculous amounts of research the last two days I've come up with what I *think* is a workable plan. This will be for running a hydraulic auger off the Front End Loader and retaining up/down, articulation (dump/curl) *and* rotation of the auger (clockwise/counter-clockwise) simultaneously.

Can you guys look over this with a fine-toothed comb and see if I missed anything or something doesn't look correct. Trying to prevent myself from making any huge mistakes and help others the heartache I've gone through trying to learn all this the past 48 hrs. (I have a dozen apple trees coming in a few weeks and I'm in a bit of a rush because I didn't realize this would be as complex as it has turned out to be)

Here we go...

Mahindra 4540 Factory Hydraulic Specs

The product brochure describes it as a "Open Center, full live hydraulic" system with 8.7gpm pump output. Manual lists PSI as "2400-2600 Max PSI" The following gauge makes mention of 2000-2500psi being "normal" as well. (GAGE FOR CHECKING HYDRAULIC PRESSURE ON 4540 MAHINDRA TRACTOR)

The loader I have (4550-4L) is controlled via a Besko HDM03 and is apparently 8.29 gpm "rated flow" (I believe this is at the PB out) The hose is listed in the parts manual as: 1/2"x2W/Bx2050L(UNF3/4"x4-UNV3/4"x4), other than the 1/2" I'm not sure what these other numbers mean.

My Proposed 3rd Function Setup

1 Station D03 Subplate Open Center ($35.95)
Style D03
Stations 1
Ports SAE 6 (ie... 6/16 = 3/8")
Size 2-1/2" x 2-1/2" x 1"
1 Station D3 Subplate Open Center | Subplates | Hydraulic Adapters & Fittings | Hydraulics | www.surpluscenter.com

Hyvair D03-35 Series Solenoid Valve (Part Number: D03SD-2C-12D-35)
12V, DIN-Style, "Standard Type", Max pressure = 3600psi, 13.2 gpm
D03SD-2C-12D-35 - 12 Volt DC

Local Tractor Supply has generic 1/2" x 168" Length County Line brand hoses for $44/ea. I was planning to use these to go from the subplate A and B ports to the FEL. (Yes, I know its TS and everyone hates them, but its cheap and they have them in stock currently) My understanding is that 3/8" hose < 10gpm and 1/2" hose > 10gpm, but since my flow is under 10gpm I wont be hurting anything by upsizing here.

...add in some SAE 6 ORB fittings for the subplate, adapters for the hoses, wiring, fuse and the control knob for the FEL joystick and I *think* that should be it for parts, right?

As for plumbing it together, I will be taking the PB out on the current FEL control and feeding that to "P" on the subplate. "A" and "B" will go to the FEL for the auger and "T" will plumb as a return to the tank.

This will all be used to run this:

McMillen X975 Planetary Drive Auger Unit
6-15 GPM, Max Continuous Operating PSI: 3000 PSI
McMillen X975 Skid Steer, Skidsteer, Planetary Auger Drive Unit, 2" Hex Drive, 6-15 GPM, 24" Max diameter Auger

Flow Specifications:
GPM, LPM, RPM, PSI, BAR, Lb-ft, N-m
6, 23, 36, 2000, 141, 1000, 1356
8, 30, 47, 2500, 176, 1277, 1731

...what am I missing? I dont know how to calculate PSI loss or if there are any glaring issues with heat buildup due to size mismatches, etc...

Thank you in advance!

 

[RNeumann]

I’d call Hyvair and verify the valve and plate is rated for that GPM with continuous (your auger) flow. They may want you to upsize the valve. They make something that is rated around 30gpm.

What I can’t confirm is if the flow rating is for intermittent use like a ram or continuous use like the auger.

 

[ericm979]

Some valves are not rated for continuous duty. I don't know if your usage % would be as much as say a log splitter but it's more than moving cylinders back and forth like a grapple.

How well you can turn the auger and move the loader at the same time will depend on the resistance to each of those things.

 

[NCFarmLife]

I just called Hyvair and the guy I talked to was clueless.... his response was "yeah, it'll wear out faster if you push it harder" - but could offer no other real information or anything helpful whatsoever to back up what he was saying. Only that continuous use = more work = wears out faster.

SMH

 

[Michael In Tennessee]

Find a NPT D03 valve and avoid extra fittings. I'm not sure on ORB fittings, but JIC fittings of the same size have smaller internal passages than NPT. I was surprised at that when i did my 3rd function.

My build is here if you want the details. https://www.tractorbynet.com/forums/hydraulics/408000-diy-kubota-3rd-function-mx4800.html?highlight=

What is your plan for a switch?

 

[ak9]

solenoid valves do not typically have relief /bypass ability might want to factor one into your design ... Keep in mind your auger rpm 47 ish is at max rpm of your engine / gear pump..even20 rpm I'd think you'd be GTG.. I know it is a lot to digest and understand ....if you have been at it for 3-4 days now you've read and learned a lot..!

I built this type of set up 4-5 years ago from scratch ...including the auger assembly which I choose to repurpose &build from a TPH PHD that I powered with a Hydraulic motor and using a few universal joints from old 4x4 drive shafts hung it from the thumb on my back hoe ...hyd fluid comes from the hoes power beyond and has relief/bypass if/when the auger sticks

 

[NCFarmLife]

Find a NPT D03 valve and avoid extra fittings. I'm not sure on ORB fittings, but JIC fittings of the same size have smaller internal passages than NPT. I was surprised at that when i did my 3rd function.

My build is here if you want the details. https://www.tractorbynet.com/forums/hydraulics/408000-diy-kubota-3rd-function-mx4800.html?highlight=

What is your plan for a switch?

That is a great build Michael - thank you for sharing! I was looking to use the ORB fittings because I read they were less prone to leaking than NPT or others. My thought was by using 1/2" hose into ORB adapters in the subplate, that *if* I had issues with leaks I could always have new hoses with ORB connectors built into them and eliminate the NPT all together.

As for a switch. I really like the looks of the Suregrip AU series, but they are really expensive.

....if you have been at it for 3-4 days now you've read and learned a lot..!

More than I ever imagined. LOL. I thought this was just going to be a quick and easy purchase...

RE: your mention of the relief valve. I *believe* the FEL controls have a built-in relief. My assumption was that the 3rd function valve could use that, but is that not the case?

Thanks again for all the help guys. I may start purchasing parts after work today since it sounds like I didn't miss anything major.

 

[ericm979]

I've read that some solenoid valves overheat with constant use. The tolerances are tight, so they might stick.

Do you want to use a valve that keeps the A and B ports open to each other (a "motor" valve)? If they're closed off the motor will slam to a stop when you turn the valve off. If I am reading the diagram right that'd be their '2f' model, except I think it also does not have P plumbed to T when it's off, and if you're putting it in series between the loader and 3pt you'd want that.

Would it be useful to have the ability to feather the auger speed like you can with a loader? A solenoid will be off and on. You'll need a mechanical valve with a lever to feather it.

 

[Michael In Tennessee]

Do you want to use a valve that keeps the A and B ports open to each other (a "motor" valve)? If they're closed off the motor will slam to a stop when you turn the valve off. If I am reading the diagram right that'd be their '2f' model, except I think it also does not have P plumbed to T when it's off, and if you're putting it in series between the loader and 3pt you'd want that.

That is a interesting question. If he does that, the 3rd function won't be good for more general work like with a grapple. Considering the drag due to digging, the bit is going to stop immediately anyway if it is engaged with the ground. Not so much if you spin it above ground.

Also, could he return the fluid to tank instead of through the B port? That would be softer, would it not? Plumb up the B port anyway for general 3rd function work, but add a third line back to tank for auger work? Not sure this works, so I'm asking...

 

[NCFarmLife]

I've read that some solenoid valves overheat with constant use. The tolerances are tight, so they might stick.

Others have mentioned this, but since I haven't been able to find any valves with "constant use" type ratings on them, I'm stuck with winging it and seeing how long it lasts...

Do you want to use a valve that keeps the A and B ports open to each other (a "motor" valve)? If they're closed off the motor will slam to a stop when you turn the valve off. If I am reading the diagram right that'd be their '2f' model, except I think it also does not have P plumbed to T when it's off, and if you're putting it in series between the loader and 3pt you'd want that.

Ideally, yes... but I think I need to keep "P" open to "T" on my implementation. I've seen one schematic with "A","B","P" and "T" all open to each other in the center position (2H on diagram) - but I think this would keep the auger from stopping or result in it jerking around when I tried to shut it off. Not sure how else to prevent. I've seen mention of "shockless" valves, but I dont know if that is referring to electrical currents or hydraulics.

Would it be useful to have the ability to feather the auger speed like you can with a loader? A solenoid will be off and on. You'll need a mechanical valve with a lever to feather it.

My understanding is that pump flow is proportional to engine speed on my tractor, so auger speed will be controlled by throttle - if I'm wrong though, I'm hoping someone can speak up.