Help Untwist my HST Brain, please...

Henro · Feb 25, 2004

Henro,

You have way to much time to think !!!!!!!!!!!


KevinJ,

Now you give me something else to worry about!

How can a guy who ( according to the wife ) doesn't have a brain, think???

/forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif

Hope she's joking... /forums/images/graemlins/blush.gif

thcri · Feb 25, 2004

( Henro,

You have way to much time to think !!!!!!!!!!!


KevinJ,

Now you give me something else to worry about!

How can a guy who ( according to the wife ) doesn't have a brain, think???

/forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif

Hope she's joking... /forums/images/graemlins/blush.gif )

I guess I would have to ask also. Henro, you have had two thats two(2) elongated threads in as little as well 1 week. Did you think these both up and hold them for this week or what. Your starting to scare me!! /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif

SacandagaBrad · Feb 25, 2004

Henro,

I'm kind of having the opposite problem, as discussed over at How much slip? in the NH forum. I would give anything to be able to stall out my TC24D in low range. A stall implies to me that I have delivered all the power available from the engine to the task. I know all about light foot pressure on the pedal to achieve a lower "gear", etc., it just doesn't stall. You'll see what I mean in the discussions rather than me re-typing everything here. It's not really a high vs. low range thing with my problem, but I thought you might find it relevant.

Brad

Henro · Feb 25, 2004

Henro...Your starting to scare me!! 

Scare you, Murf??? /forums/images/graemlins/cool.gif

I could not help but think I could even be more scary... /forums/images/graemlins/smile.gif

Let me try:

I think I might visit Minnesota SE one of these days /forums/images/graemlins/grin.gif

Murf's expression: /forums/images/graemlins/shocked.gif /forums/images/graemlins/shocked.gif /forums/images/graemlins/shocked.gif

/forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif

art · Feb 25, 2004

Your hydro is in front of the range transmision so by putting it in low range there is more torque able to be applied. The relief valve is affecting the high range hill climb.

Henro · Feb 25, 2004

A stall implies to me that I have delivered all the power available from the engine to the task. 

SacandagaBrad,

It sounds like in normal operation a HST tractor doesn't stall, but builds up enough pressure to activate a pressure relief valve and that the engine will not normally stall out, unless something else like hydraulic cylinders are also taking power from the engine.

If that is the case, and it seems reasonable, then the question would be whether the trip point of the HST pressure relief valve is high enough or not. If it were too low, then it would trip before optimum engine torque could reach the wheels.

From reading the other thread though, it sounds to me like you may have an intermittent problem in your case, rather than 100% normal operation at all times.

rockyridgefarm · Feb 25, 2004

WOW, Art, that explains a LOT!!!

Junkman · Feb 25, 2004

Henro...... I am not even going to read all 3 pages of this post, but I know what you are missing. Unfortunately, I don't know of anyone that can help you with your problems. I believe that you are suffering from a severe case of cabin fever. I would prescribe that you sit under a sun lamp until you are red in the face and need to empty those two beers in your hands to cool off. Hopefully summer will be here soon so you will have more time to spend outside and less time to spend on the computer asking question that there are no answers to. You might also consider a dog as a companion to help you through those lonely periods of the day...... /forums/images/graemlins/blush.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/shocked.gif /forums/images/graemlins/wink.gif

thcri · Feb 25, 2004

( Henro...Your starting to scare me!! 

Scare you, Murf??? /forums/images/graemlins/cool.gif

I could not help but think I could even be more scary... /forums/images/graemlins/smile.gif

Let me try:

I think I might visit Minnesota SE one of these days /forums/images/graemlins/grin.gif

Murf's expression: /forums/images/graemlins/shocked.gif /forums/images/graemlins/shocked.gif /forums/images/graemlins/shocked.gif

/forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif )

Yeah visit, I can get you a good room at the Mayo Clinic, I got connections /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

RogerH · Feb 25, 2004

Let me lend another explanation to the original question. Note that the torque (and horsepower) requirements of a hydraulic pump are proportional to both the pressure and the displacement (i.e. the flow from the pump). Therefore it is possible to generate the same horsepower with high pressure and low flow or low pressure and high flow.

Here is what may be happening. In low range, the tractor is slow, so you push the foot pedal down almost to the floor to get some decent speed. That makes the flow rate in the HST pump go way up. You hit the pile with the loader and the pressure goes up rapidly so that pressure X flow = more HP than your tractor has and it the engine dies.

Conversely, in high range you probably aren't pushing the pedal down all the way on a steep hill because real steep hills usually aren't paved and it would be way to bumpy a ride. As you go up the steep hill, the pressure rises to the relief setting, but since the HST pump flow is low, pressure X flow = less than available horsepower. Therefore the tractor stops moving but doesn't stall.

As you know, you can always prevent stalling if you can lift off the pedal fast enough. Lowering the flow rate when the HST pressure goes up keeps flow X pressure under the available power and keeps you running.

As some one else has pointed out, the John Deere 10 Series tractors does this for you automatically with Load Match.

4710and110TLB · Feb 26, 2004

Don't know if has already been said but if you are using your loader to lift and curl in a pile of dirt then that is taking away from you hydraulic power which will kill/stall the tractor the high gear uphill is it simply doesn't have the torque to move it further. Much the torque converter on a car. Just a thought!!!

Henro · Feb 26, 2004

After half-following Junkman's advice last night [only emptied one of those glasses, and substituted a reading lamp for the sun lamp] I have concluded that the only way to answer this question with sure certainty is to take thcri up on his offer. /forums/images/graemlins/cool.gif

Murf, I will be counting on you to get me a nice room at that chic hotel you mentioned if I make it up your way. I bet they have excellent breakfasts. I love a little mayo on my BLTs and other dishes, so I can tell you are a master of selection just by seeing that place's name! /forums/images/graemlins/smile.gif

My plan is to contact Murf by private message, when the time is right, after assembling some reading material. I will need to take something extra, because the wife just gave me "that look" again when I suggested we head up Murf's way, to stay at a fine local establishment he had recommended. I told her the name of the place Murf recommended and she gave me a special, understanding look and the matter appeared settled. /forums/images/graemlins/crazy.gif I guess I will be going alone… /forums/images/graemlins/frown.gif

The only appropriate reading material I can think of bringing is a couple tractor maintenance manuals. Maintenance manuals along with being interesting most of the time, have the side benefit of putting me quickly to sleep if opened late in the evening. I better get on the phone to my dealer and order the manuals I should have bought last year. /forums/images/graemlins/blush.gif

Many thanks to everyone for thier input. I now have an "understanding" of what may be happening to HST tractors when they do things differently than a gear tractor would... /forums/images/graemlins/smile.gif The manuals should show me if my perception and reality are close to being the same... /forums/images/graemlins/wink.gif

Murf, the wife made a passing comment about the white uniforms everyone wears, at that place your recommended, on the floor where I'll be staying. Wonder what that’s all about. /forums/images/graemlins/confused.gif

thcri · Feb 26, 2004

(

Murf, the wife made a passing comment about the white uniforms everyone wears, at that place your recommended, on the floor where I'll be staying. Wonder what that’s all about. /forums/images/graemlins/confused.gif )

If she is questioning the white uniforms I wonder what she is going to say about all the padded walls??? /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

Murph

txdon · Feb 26, 2004

We'll leave the light on. /forums/images/graemlins/grin.gif

5030 · Feb 26, 2004

Alright Bill........

I read it all and I come to the conclusion that you indeed have a bad case of retirement cabin fever. The holes in the ROPS are one thing. I think the whining isn't coming from your HST, it's coming from inside your head!!

If you want to really drill something, why don't you drill a small hole in your HST case. That would eliminate the whining as well as forward movement!!

Just think about this summer. I'll come with the camper and you, me and Cerberus will go fishing up on Meade Run. Of course we will invite Mike (Pa) along and everyone else, especially those North East boys. Think about warm weather, outside, grass growing and mosquito's biting.

Seriously, I did like the whirlpool bath at the Holiday Inn. Especially that the company paid for it. I really needed a massage but there were no massage parlors nearby!!

Double seriously, I can stall the 5030 in "H" range but only if the rpm's are at an idle. Same applies in "M" range. In "L" range, it just spins the wheels. I never tried it on concrete, I am afraid it would snap an axle.

keeney · Feb 27, 2004

I think that what is happening to your tractor is what you want to happen, and here is why:

1. Without a pressure reliefs, the engine would be stalling all the time whenever the required torque to spin any or all of the pumps goes too high. Every time a cylinder hit the end of its travel or the tractor was unable to pull or push something any harder, the engine would stall. (or a hose or seal might pop). This would make it hard to use.

2. If the sum of all the PRV's was set to never exceed the available engine torque, then the engine would never stall, but you could never deliver full engine torque to any one part of the tractor. Say we divided the torque evenly between HST, steering, and loader. Each would always have a mximum of 1/3 of the available torque of the engine. The loader would be whimpy, the push/pull would not be very useful, and your steering would be imitating JClark's machine.

3. So the compromise is to set each PRV slightly below stalling torque. Say maybe 80%. Any one system can be used with nearly the full power of the engine and still have a minimal amount of remaining torque to at least run the other systems with no load. But, if you max out more than one system at a time, the engine stalls.

4. Many one-pump (not including the HST) systems give "priority" to the steering. This is kind of a safety thing. You wouldn't want the steering to stop working while the tractor happily chugged off the side of the road.

5. Like the I-match system, you could have one of the other systems back-off its load if the engine starts to stall. On I-match, they chose to back off the HST. A very good idea when running a tiller or a loader. You can still get full power to the implement, you just move slower.

Many tractors are in situation 3. Some are in 4. Some newer tractors have situation 5.

- Rick

ljh2 · Feb 27, 2004

What kind of tree was that again? What happens when you push it over? When it falls will it make a noise? Will you be able to hear it over the HST whine? All in all, sounds like you need a BIGGER tractor! /forums/images/graemlins/smirk.gif /forums/images/graemlins/smile.gif /forums/images/graemlins/cool.gif