Plowing & pushing HST to the limit

[dieselpwr]

JimI

I'm just wondering what range you were in when you were able to make your machine stall out. My experiences have been more like djradz. The engine just slows a little & the wheels quit moving in all but range I-turtle. In range I-turtle I just spin my wheels. As of yet I guess I haven't encountered enough traction to make it lug down enough to stop the motor in low or even slow it much for that matter... I've tried but I just spin 'em in 4 wheel dig w/ diff loc activated (full loader & a 500# blade hanging on the back) Maybe my relief valves are set too light & that's why I can't lug it way down in any of the upper ranges??? (which would be unfortunate as they are not adjustable & therefore need to be replaced if not set correctly) Any others with an opinion / experience out there. I'd like to here from you.

Troy

 

[DVerbarg]

Troy,

Regarding, "In range I-turtle I just spin my wheels", this is true for me also, unless one of two things (or both) are true: throttle below 2200 RPM and activating FEL lift and curl at the same time while in good traction conditions. I don't know if it makes much difference but I just realized that I also have a toothbar on the bucket which has greatly increased my capability to get a "good bite".

DaveV

 

[jinman]

Troy, when I am in loose dirt doing loader work, I can spin my wheels in low range and differential lock without a problem, even with my heavy box blade on the rear. How I stalled my tractor was pulling a load with a chain hooked to the box blade and the box blade just off the ground. I was on solid soil (never tilled) and grass (little bluestem). I'm sure the traction was 90% rear, on new R4s. The pull on the chain shifted all the weight to the rear and downward so that I obtained "super" traction. I also had the differential lock engaged. The rpm was above 2700, so I know my torque/hp was at its highest (actually I think the torque peaks lower). In case you think something wasn't pulling good, the chain I was pulling was around a brush pile with a Kubota 3410 on the other end. I was pulling him backwards for about 10ft before the stall. We tried it the second time and broke a 3/8" chain. Almost every link was flattened. BE ADVISED THAT I DON'T RECOMMEND THIS. Hindsight tells me that the chain breaking could have been dangerous. It's just a story that illustrates that you can stall a NHTC45D in low/low if you have enough traction. It doesn't speak to any other size or brand of tractor. In higher ranges, I can feel what I think is the relief valve "lifting," but not in low/turtle. It just pulled 'til it couldn't pull no more./w3tcompact/icons/tongue.gif

JimI

 

[dieselpwr]

JimI

That's really interesting. Now I am wondering. It seems odd that these machines seem to stall the wheels (pop the relief valve) pretty easy in the higher ranges without lugging the engine down much. But then in I-turtle they will apparently pull until the engine can't keep up before popping the relief valve? The question in my mind is why. What could explain that? Can the hydro & gearing & transmition order be the big missing link here? It just seems to me you are still applying all the torque to the gearcase from the engine with high pressure hydraulic fluid - no matter what range right? Supposing the valve is between the hydro & the gearbox - why wouldn't it drag the engine way down in the other ranges before poping the valve? Or am I missing something obviouse here? Maybe the order all these things are arranged in that makes the majic? I just love to know how what's inside the "little black box" works. Questions questions questions... /w3tcompact/icons/crazy.gif

Troy

 

[jinman]

Troy, I don't know the "why" yet, but I am going to dig through my Maintenance Manual and see if I can find a clue. I'll get back to you if I have some great revelation of how the hydro works.


JimI