Lugging Engine

[JMER817]

Ok, we all know that "lugging" a tractor is not good for it. What do you consider lugging? For light loads and driving around I keep my RPM right around 1700-1800. That puts it right at the "economy" PTO recommended range according to my speedometer. I don't like driving "wide open" all the time, feels like I'm wasting fuel and creating excessive wear. I put a video of my JD4120 at different RPM levels. Hydro take off in med range, no load, loaded tires in 4x4. From idle, 1500 rpm, and 1750.

https://www.youtube.com/watch?v=Chj6e228tqY&feature=youtu.be

 

[SandburRanch]

Lugging is when the engine RPM won't respond to more throttle.

 

[skyhook]

Lugging is when the engine RPM won't respond to more throttle.

Ya, I think that pretty well explains it, it's when you need to gear Down or the engine may stall.

 

[Dave M7040]

The opposite of this is "diesel slobber."
Goggle it and you will learn that diesel engines need to operate under significant load or problems develop.
Dave M7040

 

[drizler]

The opposite of this is "diesel slobber."
Goggle it and you will learn that diesel engines need to operate under significant load or problems develop.
Dave M7040

One easy to spot sign is that "diesel rattle" when you ask for more power. It's easy to pick up on as it sounds like a couple of bolts rolling around in an empty can. I usually keep mine around 1500 and use the foot throttle to goose it for more rather than let it rev high all the time.
Here is a good one for you guys who have slobbering. I got this from some old Cat mechanics. They would take scouring powder and fluff it into the air intake with the cleaner removed. They just kept it coming and reved **** out of it till the black raindrops on the hood went away. No it wasn't the modern stuff for no scratch sinks either but good old COMET. Hows that for a hone job quickie? Of course the prevention is don't let it sit idling forever and running a very low power.

 

[Tx Jim]

The opposite of this is "diesel slobber."
Goggle it and you will learn that diesel engines need to operate under significant load or problems develop.
Dave M7040

IMHO engine operating temperature or lack of correct temp affects diesel slobber AKA wet stacking.

 

[JMER817]

How do the big trucks get by idling all night?

 

[JerryK]

Big trucks sometime use a ' high idle ' to raise the RPM enough for the engine to make heat. I have a kit in my Dodge Cummins that uses an old GM solenoid to raise the idle up. Most diesels have such a big iron block and cooling system that it takes something more that low idle to make enough heat to have somewhat effecient combustion temps.... Trucks also sometimes have a diesel fueled coolant heater to make heat....

 

[JMER817]

Big trucks sometime use a ' high idle ' to raise the RPM enough for the engine to make heat. I have a kit in my Dodge Cummins that uses an old GM solenoid to raise the idle up. Most diesels have such a big blocks and cooling system that it takes something more that low idle to make enough heat to have somewhat effecient combustion temps.... Trucks also sometimes have a diesel fueled coolant heater to make heat....

Thanks for the explanation

 

[JerryK]

Thanks for the explanation

No problem, us old guys have lots of time to run our mouth... just need folks gullible enough to listen.. I knew guys that pulled their fans sometimes in the winter, and lots of guys run something blocking the radiator air flow. Probably all trucks have different personalities. Dodge Cummins also has a three cyl idle where it runs on only half the cyl's to heat up. I have never enabled that on my truck. I have blocked my radiator before, leaving a bout a 12" opening directly in front of the fan. My old John Deere used radiator flaps in front of the radiator that you had to manually open/close to regulate engine heat. Did not have a thermostat in the big radiator hose....

 

[SPYDERLK]

Lugging is when the engine RPM won't respond to more throttle.

Lugging is when the engine is below its normal operating range [~ < 1500] and won't respond to more throttle.

 

[SandburRanch]

Lugging is when the engine is below its normal operating range [~ < 1500] and won't respond to more throttle.

Or when it's within 99 percent of its upper limit and won't respond to more throttle.

 

[SPYDERLK]

Or when it's within 1 percent of its upper limit and won't respond to more throttle.

So you would downshift?

 

[drizler]

Downshift , lower range selection for axle, or rev up the RPMS, or some combination of the above. With my new tractor I find myself between ranges constantly as moving around is better in Hi Range but I have to put in in Mid Range to push into dirt piles. I can do it just like with my old one at higher speed and use the machines forward momentum like I had to in that case but it's smarter to just downshift ranges and or gears . The machine appreciates it .
Mine likes it between 1500 and 1800 for things like dirt work or the back hoe. If it's just a pile of dirt down towards 1500 and if digging hard stuff the higher end. It's a bit subjective but you will get it in time.
You should have an owners manual like mine. Through the wonders of modern translation the Japanese version of break in is "run the engine at FULL THROTTLE at all times for the 1st 5o hours:shocked:" . The Folks at Mitsubishi must have been trying to get revenge for the war. The dealer and I both laughed that one off but it was a new model and he hadn't seen the book yet. When they are new though (unless you have a new 36HP Mitsubishi with my manual:confused3 you do want to run it hard and keep the rpms way up there for break in though.

 

[RaydaKub]

I grew up on a farm, and I remember plowing some alfalfa. Most of the field, things went really well, but along a fenceline the old 930 dropped from WOT 1950 rpm down to about 1200. The cloud of black smoke could be seen for a mile. She would lug through that 100 yards or so, but then pick back up and keep right on cranking through the rest of the field until the next round in that same low spot. I never thought of that as being harmful to the engine, and my dad would have done the same thing. I remember downshifting on one round, but then it seemed so slow and pointless because it didn't pull down at all, although there was still a little bit of smoke, so I didn't do it anymore. Was this a bad thing to do? That engine had several thousand hours on it when it was sold and still ran great.

 

[GManBart]

I've heard some diesel mechanics state that lugging the engine starts to be a problem when the RPM is low enough that the oil pressure drops significantly.

The point they're making is that high load on the crankshaft, connecting rods, pistons, etc with low oil pressure is the worst combination for engine wear.