Is stalling the tractor an automatic fail on the road test?

Started to see driveshafts built to fail at around 1300 foot pounds in 2000. Among the newer FFE tractors. Not acceptable because those engines had almost 1600 foot pounds. Sliding tandems became a .. poker draw on the river as it were.

I don't expect you new ones to understand that just yet. That will come.

Lugging you have a torque, call a Detriot 500, you got around 1250 I think it is for torque, or 1350 I cannot recall. High horse was around 1600 with redline at 1950. Horse drops off past 1600. Your torque drops off past 1300 roughly and if you go slower the other way say upgrade below 1300 your torque also drops off. Then at about 1100 you begin to buck, literally fighting to stall that engine itself from rotating.

It's stupid.

Once in a while we get to yakking and lug down for the top to see who shifts last. It's a game, there is a way to do that. The lower your rpms drop, you eased up on the fuel as it were once she quits pulling worth a ####. Hopefully your momentum is bigger than the big talker next to you. Shift down really quiet like and then add fuel at 1600 But don't let her snort. (Jake etc)

 

Since I think that ignorant supertrucker comment was aimed at me I will reply. It is a thing that some ####### will come into a forum and try to be funny because they get so filled with verbosity it just kills them to not say something. I stand by every WORD typed in this thread. I am on point and what's more I am right. learning to control your RPM's is something that should be learned BEFORE you get finished in school and practiced time and time again as you do your range/backing work before that official skills test. Shifting in a truck is not about RPM control as much as it is about learning how to shift and when and where. RPM control is more basic then that. Even the OP understood they made a mistake. Then said RPM control becomes part of the platform you begin learning on as you jump into that trainers truck and learn by doing day in and day out until it becomes 2nd nature. However if you have not mastered basic RPM control it means most likely you are also lugging a lot and burning a clutch. Many years ago back when Schneider was using those International Eagle cab overs I watched a new driver smoke a clutch. I asked him how long it had been since he started driving solo. He said oh about 2 years. All I could do was just stand there with a stupid look on my face.This was at least 20 years ago.This driver smoked that clutch so bad drivers 20 and 30 feet away were looking at him. This is why drivers do Thousands if not Millions in engine, clutch, rear end and premature brake damage every year. I guess if you were paying those bills you would still say oh nobody was born with a shifter in their hands everybody has to learn. However something tells me you would be a bit more supertruckerish..

Edited to add I once worked for a man that took ALL money spent to fix vehicle abuse OUT of everybody's bonus every year. I have seen those bonuses be as high as 3 or 4 thousand. We had a moron driver that destroyed 2 engines and rolled a dump truck at the quarry destroying the dump body and the tractors 5th wheel had to be replaced.. That year my bonus was $250. I could have shot that #######. I was really counting on that money because I was hoping to use it to pay off my car.

 

I found this posted and thought I would post it here. In this example the engine discuseed is in a pickup I believe, but the basics are the same.

"Lugging" is basically the act of operating an engine under a load at a lower RPM than it can properly function, or is designed to operate efficiently. We are all pretty familiar with the term "hydro-planing" - it is often used to describe a situation out on wet roads, where a vehicle reaches a speed where the tires no longer are in contact with the roads surface, but are actually "water-skiing" on top of the water - a dangerous, no traction scenario in this case!
Hydro-planing can be reduced or eliminated by increasing the WEIGHT of the vehicle, reducing SPEED so the tires can "settle" back down to the roads surface, or reducing the "contact patch" of the tire in relation to the weight applied to it. . .
Let's apply all the above to internal engine operation. . .
An engine is designed with a specific lubricant flow, and internal parts clearances that allow components to "hydro-plane" on an oil film - not actually allowing components to come in contact with one another. This hydro-planing action demands that certain conditions MUST be maintained - proper lubricant flow and density - viscosity - and relative SPEED of moving parts to maintain constant proper hydro-planing action.
IF relative engine component SPEEDS are reduced too far, the hydro-planing action is compromised, parts break thru the protective oil film, and metal-to-metal contact takes place - the same happens if the LOAD is too high, or the contact patch - or cushion - is too small - That's why LARGE connecting rods and main bearings are BETTER than SMALL ones! It permits a larger contact patch, and subsequent oil "cushion" to prevent contact between adjacent parts.
The engines in our trucks are designed to carry heavy loads at relatively LOW engine speeds - but as good as they are, they STILL must be operated at sufficient RPM as to maintain proper lubricant flow, and component speeds to maintain oil film strength - in other words, don't "lug" the engine down so low in speed or load as to compromise oils ability to isolate components from each other!
What suffers most in lugging situations?
Main bearings lose lubricant isolation, and begin contact with the crankshaft - pistons and rings begin rocking and wobbling under combustion pressure, contacting the cylinder walls and accelerating wear - similar activity also take place in the drivetrain it transmissions and differentials, where heavy loads at low speeds allow individual components to break thru the lubricants protecting film, and come in contact with each other.

Bullhaulers wife asked me once to always credit a website if I use their material.

This is from turbodieselregister.com. I won't post the actual link unless An admin asks me too.

 

Wow, pot, meet kettle.

 

bliteus belua es!

 

Thanks for proving our thoughts about you correct, Supertrucker.

 

After several minutes of in the floor laughing about this I was reminded in FB about something VERY much like this. When a kid is learning how to drive (automatic or manual it don't matter) they sometimes develop the habit of allowing sudden jerking movements as they try to drive. I have seen Drivers License Examiners Fail for doing this in an excessive way. This is the same with lugging. When you lug you are demonstrating a lack of control.

 

I'm going to hop out of this thread unless an intelligent reply is made that I might want to reply too. OP to answer your question I am not sure if a stall will get you failed. I think being failed would be more about what led up to said stall. Speaking of stalls there are few if any old hands that have not stalled a tractor. Hell I have stalled my old S-10 pickup many times because of my clumsy foot slipped off the clutch. I have done this more times then I care to admit in trucks too. It happens you restart and move past it. However lugging an engine to the brink of stalling it should NEVER be done, not even by a student because an instructor should be in your rectum real quick if you do it.Just make sure you tell that instructor Mater tua tam obesa est ut ### Romae est urbs habet octo colles! and both of you go have a beer afterward.

 

I suspect that the availible knowledge might be a bit excessive for someone who is afraid of stalling out. I hate to think what the truck of the future might look like when Engineers understand how to make engines that do not stall at all down to 100 rpm. /sarc.

 

You're very correct, with experience any driver should be able to shift without looking at a tach. BUT, the OP doesn't even have his CDL yet. No need to be a ####### to him, he's still learning. But, he IS learning by recognizing mistakes, and asking questions about them.