TC system / a helpful helper spring?

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TC system / a helpful helper spring?

Postby DavidG » Tue Mar 12, 2013 7:38 am

Thanks to Scrivet, Rudi and Engene for help on the white froth/gunk thread. The question has turned into something purely about the hydraulic system so I think a new post makes sense.

I've read the TC specs quite a bit -- not claiming to understand them 100%, but I am aware that exceeding them is no good so I found a scale and I plan to do the math on everything to make sure weight on the hydraulic rockshaft is going to be okay.

But, how about this -- the max weight off the rear is 600lbs, says GSS-1024. Well, turns out my system could only lift 400 :? If I tried to lift 450lbs that's not over the max, and so internal components should be okay? I'm thinking a concern is a check valve might be hurt if lifting over 600lbs, or something like that?

Just to say, I'm not planning on getting right up to 600lbs and I'll leave a good safety margin. But if I max out my current capability of 400lbs, like by trying to lift 450lbs, does anything happen since that's well under the system's rated max? I don't mean leaving it struggling, I just mean trying to lift and immediately putting it down when I see "oops it's too heavy."

And in any case, it's clear what I need: A HELPER SPRING! It seems that the job of the fast hitch helper spring is to reduce the load on the hydraulic rockshaft by cancelling out the added downward force/weight of the fast hitch. Is there a reason this wouldn't work for anything that's attached to the hydraulics, front or rear? Theoretically something could be too *light* and so the system has to do extra work just to extend the spring, but I'd be aware of that and not use the helper spring in that case.

The real question: Does a helper spring allow the hydraulics to lift something that was otherwise too heavy, OR does it just make an *easier* lift out of things that were possible to lift, without the spring? The reason I ask is that when the front rockshaft is rotated back (down) as far as it goes,the helper spring arm seems to point directly at the helper spring bracket between transmission+fender. Which means that when an implement is all the way down, it seems the spring is not being much help in pushing the rockshaft back up, since most of its force is directly in line with the rockshaft helper spring arm. Maybe that's the point, since as the spring compresses it exerts more and more force, and so the rockshaft design modulates that...

Anyway, I'd appreciate any helper spring thoughts.
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Re: TC system / a helpful helper spring?

Postby John *.?-!.* cub owner » Tue Mar 12, 2013 9:27 am

Before doing any modifications, you need to get a pressure gauge capable of readin1200 pounds, and connect it to the top plug where the lines go to the block. go here, and follow the instructions for testing
http://www.farmallcub.com/fcman/downloa ... ontrol.pdf
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Re: TC system / a helpful helper spring?

Postby Matt Kirsch » Wed Mar 13, 2013 9:33 am

A helper spring is not an excuse to overload the tractor. It is just there to assist with the rated load.

Remember it's called a helper spring not an abuse spring.

Now I thought 400lbs was about all you really wanted to lift with a Fast Hitch... I know mine will lift quite a bit more than that because it will pick up the tongue on my enclosed trailer, with or without the helper spring. IMHO 600lbs is really pushing it.

If it will lift 400lbs then I'd be happy and call it a day.
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Re: TC system / a helpful helper spring?

Postby Eugene » Wed Mar 13, 2013 1:41 pm

DavidG wrote:if I max out my current capability of 400lbs, like by trying to lift 450lbs, does anything happen since that's well under the system's rated max? Anyway, I'd appreciate any helper spring thoughts.
The touch control block contains a pressure relief valve set at 1200 - 1500 psi. Once pressure on the hydraulic oil reaches the pressure relief valve's preset point the valve opens up. Trying to lift more than the hydraulic system's capacity will simply open up the pressure relief valve - load is not lifted/moved.

Helper spring. Yup what Matt said.
Matt Kirsch wrote:If it will lift 400lbs then I'd be happy and call it a day.
I have an excuse. CRS.
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Re: TC system / a helpful helper spring?

Postby DavidG » Wed Mar 13, 2013 4:21 pm

Thanks for pushing me to actually do the pressure test. Turns out 1500psi gauges aren't as expensive as I'd expect, so I'll find one and check it out.

Just to be clear -- I'm not trying to overload what the manual says the system is rated for, or to overload the tractor frame or tip over by hoisting something too heavy. I'm just hoping to lift closer to what the manual says the max is. And if I look for a helper spring to do that -- using it essentially for the same purpose as with a fast hitch -- can you say more what the danger is?

Eugene, that's what I'd expect of the IH engineers, that there's a safety valve in there to save the system from farmers maxing out their tractor :roll: . But I also read in a number of posts about the danger of overloading the hydraulic system, blowing out o-rings in the pump, etc. What you said indicates that there's no danger in trying to lift something that won't go, since that just means the relief valve's open, as designed. And it doesn't matter how much too heavy something is, since once the system's putting all its psi into it, it doesn't know how much weight it's held down by. Maybe it's just shy by one pound, maybe 1000lbs, still the load is too heavy and doesn't move.

I appreciate folks' caution, as I go toward what is admittedly in a gray area of Cub use. I'm not trying to get away with anything dangerous, I just want to understand which things are *in* a danger zone and which things are getting close, but are actually okay.
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Re: TC system / a helpful helper spring?

Postby John *.?-!.* cub owner » Wed Mar 13, 2013 4:34 pm

Be careful how you interpret what the touch control manual says. 2 wheel weights mounted on the rear lift arm with a chain are = to 600 pounds at the rockshaft, which is half the PERMISSABLE weight for the cub. It is not stating it should or will lift 600 pounds at the rear lift, just that is the permissible maximum. With time, wear, etc. it will have reduced, also if they are farther out than the end of the rockshaft, the total will be reduced due to leverage.
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Re: TC system / a helpful helper spring?

Postby Eugene » Wed Mar 13, 2013 6:41 pm

DavidG wrote:But I also read in a number of posts about the danger of overloading the hydraulic system, blowing out o-rings in the pump, etc.
Personally I don't recall posts about overloading the hydraulic system and blowing out o-rings. Yes, hydraulic hoses and seals fail, sometimes in a dramatic fashion because of the hydraulic pressure and pump volume. The failures are normally accounted for by wear and/or old age.

Typically items are engineered to withstand 2 to 3 times their rated or advertised load.

My perspective. If the machine/tractor won't pick up the load - get a bigger machine. If the machine/tractor pickups up the load and it (tractor/machine) becomes unsteady, either reduce the load or get a bigger machine.
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