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[Joe Liter]

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[rScotty]

Is the shuttle shift working correctly? How about the hydraulic pump? Power steering??

If so, give thanks for having good luck and about all you can do is what you have done. I'd monitor the hydraulic oil temperature to make sure that it is staying in bounds, and hope it eventually washes everything through. You may have to flush it several times. Probably will. That high sulpher gear oil is sticky and hard to remove. Especially hard to flush out when there are parallel paths like in the hydraulic radiator or any control valves.

The proper oil is a lightweight trans/hydraulic oil - there are many brands of trans/hydraulic and all will work. Or at least all will work better tha either gear oil or hydraulic oil. Those are both very different fluids than the recommended oil.

If you can still smell the gear oil, chances are that the first gear oil you put in it was the old style single weight - probably 90 wt. - gear lube. And the smell means you didn't get it all out. Those old style gear lubs were high sulphur oils - hence the distinctive and powerful smell. They were deliberately thick sticky oils designed to still be useful at low temperatures and nobody ever expected gear lube to be used in high heat operation like a hydraulic pump and FEL.
In fact, I doubt gear lube would even flow tevenly hrough a hydraulic radiator. It might just sit there blocking half the tubes. So check that - check If your system has a hydraulic radiator, it might still be plugged with gear lube. Anyway, gear lube would certainly cause a hydraulic system to overheat and overheating could affect the joystick as well as other things. .

Assuming it has the right oil now, it sounds like the big problem is more flushing, watching the hydraulic temperature, and that sticky joystick. Are you considering replacing that joystick? A joystick is minor compared to what could have happened.

rScotty

 

[rScotty]

thank you for responding
Is the shuttle shift working correctly? Yes
How about the hydraulic pump? It appears to be
Power steering?? yes
hydraulic radiator - the best I can tell there isn't one on my tractor but willing to double check
Joystick - at first startup the joystick is fine, its just when it gets hot is when it gets hard to move & feels like it has pressure built up in it
What would be the best way to continue flushing & or how often?

Interesting question on flushing. I don't know. I do know that there are incompatible fluids that will cause all kinds of oddities because it happened to me two days ago. I've got some gear lube in the shop right now that I must have gotten something incompatible from the funnel I used to pour the extra back into the bulk container. I started to use it two days ago it had jelled!! Big chunks of what looks like clear jello in the container floating in what was left of the lube. Oddest thing. I've never seen that before.

I don't know how you would get that kind of crud out of a system.

So... lets backup. before you decide on flushing, look up and find out whether you have a hydraulic cooling radiator because that is a likely problem. All HST have them, but only half the shuttle shifts do. If so, task one would be to figure out how to purge that radiator.

LATE EDIT: check for a cleanable sump filter in the bottom of the transmission. That might be better than the experiment that follows...

Next, you need to see what happens when you mix those oils and lubes.... We need to know if we really have some sort of oil incompatibility problem or are we barking up the wrong tree.

Here is what I would do. Hopefully you have some of that old gear lube left from the initial screw up. And some of the hydraulic oil you used as well. And some of the new oil the dealer used.
Get some mason jars with lids and check what happens if you mix those oils together. Does one dissolve the other? Do they form jello? Gear lube is high-sulfur petroleum oil with lots of odd additives. Some hydraulic oils use an alcohol base instead of petroleum. I've no idea what mixing that combo might do. Maybe gently heat them in hot water (that's why you want lids) and see what happens.

What you want is to see that the new oil from the dealer can dilute or dissolve the worst case mix of that old stinky gear lube you used and/or hydraulic oil. If so, then everything is fine and we know several changes might fix it. If you get jello - like I just did with my gear lube in my shop - there is lots of bolting, cleaning, and maybe some swearing in your future.

There may be no hope for the joystick. They are full of parallel passages and tiny orfices and not made to be taken apart and cleaned. How much are joysticks these days?

I wonder if looking at the hydraulic filter might tell you anything? Does it have a cleanable sump filter in the transmission? If so, that is as good as a mason jar experiment.

rScotty

 

[duffer]

All great suggestions from rScotty.

I'd call a local hydraulic shop and see what they say as well. Somebody who works on excavators, big trucks, etc. IMO they are more qualified to diagnose your problem than (most) guys in the back of a dealership that are prepping tractors and implements for delivery.

 

[D&D]

Have you (or someone) checked the loader control linkages for sticking/binding?

 

[oldnslo]

Like D & D I suspect a problem with the mechanical linkage of the joystick control. Once warm if you shut the tractor off is the joystick still hard to operate?

 

[D&D]

Like D & D I suspect a problem with the mechanical linkage of the joystick control. Once warm if you shut the tractor off is the joystick still hard to operate?

Too often we get hung upon what happened last vs what’s broke now. I’ve certainly been trapped on that hamster wheel before.

 

[oldnslo]

Yes

Yes still hard to operate when warm with engine off?

Can you see the control valve? If yes one end would be connected to joy stick. Is this connection direct mount or via push - pull cables?

Other end there are caps or covers usually held on by two or four screws. Is there any evidence of oil leaking out around these covers?

 

[rScotty]

Like D & D I suspect a problem with the mechanical linkage of the joystick control. Once warm if you shut the tractor off is the joystick still hard to operate?

That would tell us something.... but I'm not sure what. Certainly it is worth trying though. I wonder what that will show?? Hope he makes the experiment.

The problem I'm having is that the joystick has a bunch of parallel return passages & I can't figure out how to separate which passages do what functions.
That's why I'm opening the door on the possiblity of replacement.

For example, opening the flow to extend the bucket cylinders simultaneously opens a set of parallel - probably dogleg shaped - small return passages inside the control valve. Double that number of potential blockages for when the valve is moved the other way, and double it again it if any regeneration is involved.

I think a few old hydraulic guys can figure out how to test the pressure side of the control valve, but testing the return side when the passages are parallel is more difficult. Especially without knowing exactly how it is plumbed inside.

Maybe we will know more over the next few days.

rScotty

 

[oldnslo]

I doubt any extra passages on this valve for pilot oil since it is mechanically operated and also doubtful the gear lube would cause failure with increased temps. If anything the increased temps would allow oil to flow easier.

Is this valve multiple sections held together via tie rods or bolts? If these were took apart was it assembled in a manner that is causing mechanical binding as it heats up such as tie rods tightened to tight? This can and will cause spools to bind.

 

[rScotty]

I doubt any extra passages on this valve for pilot oil since it is mechanically operated and also doubtful the gear lube would cause failure with increased temps. If anything the increased temps would allow oil to flow easier.

Is this valve multiple sections held together via tie rods or bolts? If these were took apart was it assembled in a manner that is causing mechanical binding as it heats up such as tie rods tightened to tight? This can and will cause spools to bind.

Yes, I didn't think of that. Maybe it is a sectional type. If so, it could be disassembled, cleaned, and tested. I've never seen one like you descibe used as a 2 spool loader valve - but that means little.

I have seen those multiple section valves held together that way in backhoes and rear remote stacks, just not in loader valves. In fact, taking mine apart is on the "to do" list.

I'm taking a break from shop work. I'll search for it.

LATER.... I can't find a single example of a multiple section 2 spool loader control valve. All I find are standard monobloc body type. That doesn't help.
Have you got a link?
Maybe the Europeans make one or maybe Mahindra found a stash we don't know about.

Keep the ideas coming - at worst the OP can gamble and replace that joystick for 2/3 hundred bucks and an hour's work. Sure beats the other problems he might have had with PS and shuttle.

rScotty

 

[oldnslo]

If accessible disconnect the push pull cables from the spools. That would then separate the joy stick from the valve spools. He could then manually move the spools and joy stick to see where binding is.

I have also not seen a standard loader valve that isn’t a mono-block design but did Mahindra mount this valve to a casting like some rear remotes?

Pictures of valve would certainly answer some of these questions.

 

[oldnslo]

Parts breakdown certainly looks like a mono-block assembly.

Did this problem start before the valve was taken apart or after? Since problem gets worse when warm I am leaning towards something expanding and binding which would point towards the valve but what changed to cause this?

 

[oldnslo]

How difficult is it to access where the joy stick cables connect to the valve? If not to difficult could you disconnect the cables when unit is heated up and binding to isolate valve problem or cable problem?

Cables can corrode and bind just trying to imagine a scenario where heat would make them bind worse and why after 50 hr service.

Valve binding after 50 hr service doesn’t make any sense either.

 

[oldnslo]

Air would make the loader spongy but should have no effect on how the joystick moves.

 

[Rich B1]

If you had the valve off and apart, is it possible you overtightened the mounting bolts when the valve was reinstalled?

It is also possible the valve was shimmed to avoid being put in a bind when mounted if the mounting plate is less than flat. Loosen the mounting bolts a it and see if the valve gets a gap under one or 2. If so, you may need to shim it to avoid binding the spools when the bolts are tight.

 

[rScotty]

Its not to bad to access, the cables looked fine when we took the valve off an cleaned it, it may have been doing from the word go, i got the tractor in Jan. of 2020 an only used it to put in hay for the cows, moving wood for the heater, not much run time all at one time. The dealership said it was air in the system.

OK. So what I'm hearing is that maybe the joystick being stuck has nothing to do with the wrong oil at the 50 hour service. Maybe it was always that way and you are just noticing it now that your running the tractor on longer jobs - long enough that the tractor has a chance to get warm...or hot.
And the joystick works normally when cold or for the first half hour.
And the joystick has been getting sticky now long enough for you to get it flushed twice and someone to take the joystick apart and check the O rings.
And the dealership said it was air in the system.

All that about right?

BTW, I doubt air could cause a problem in the Joystick. It might cause the whole hydraulic system to overheat, though.

That type of hydraulic system is common to almost every compact or utility sizetractor made. All of them will normally self-purge of air in 5 minutes or so. The only way long term air in the system could get there is if there is a loose connection or bad hose allowing air to enter the the suction side of the system as the tractor is running. Air leaking into the hydraulic system can only happen in the suction portion which is the lines between the transmission sump, the hydraulic filter, and the line up to the hydraulic pump.
Air leaking into a hydraulic flow is pretty easy to find and cure. if you have a leak it willl not show any symptoms to tell you where the air is getting in until you turn the motor off. Then there will be a minor drip that wets the outside of the hoses. Typically it can be as subtle as a few spoonfuls of oil under the tractor after it sits all night. Or a hose that is wet on the outside of the hose.

An air leak in the suction side of the system will make the controls feel spongy and makes the cylinders work differently at the end of their stroke than at the middle. Also asuction airleak is instantly obvious to the experienced mechanic because the return hydraulic oil in the sump has so many microbubbles that it is no longer clear. It looks murky - but then it clears up and becomes clear oil again after sitting overnight.

Is any of this sounding famiiar?

rScotty

 

[Rich B1]

Thank you Sir, The problem was before the valve was taken off an cleaned.

The mounting plate may have been less than flat from new if that is the case. It is worth a check.

 

[rScotty]

Can not say that I've noticed anything under the tractor. there again not really looked. I'll look the tractor over good an check fittings an hoses an put down some cardboard after i have run it. i thing the bubble thing you spoke of may be the problem I'll run some in a clear jar an see. Yes i think you are on to something here it does get hot.

The other thing that will make hydraulics hotter than they should be is if there is a restriction in the pressure line. Anytime oil has to be forced through a small orfice it gets hot fast. You can heat up your whole hydraulic oil supply in a minute or two by holding the steering against the stop until it begins to whine.
In fact, JD recommends doing that on their big 310 backhoes if the oil is too cold to flow on a winter day. ...

And of course the other thing is that there may be an obstruction somewhere doing exactly that. Something could have clogged or broken loose internally and be jamming up the flow. It happens. If so, a pressure gauge will find it pretty quickly.

If nothing else works, and the problem really is just the fluid getting too hot, you can always add a radiator. It beats fixing a tractor.

rScotty