I have a bunch of questions about driving trucks/ tractors. First question, as dumb as it may be, are the terms "truck" and "tractor" used interchangeably?
One thing I've read a lot about is the shifting. Difficulty up/ down shifting, floating gears, and double clutching.
What is the purpose of double clutching? Why can't you simply push in the clutch and hold it there until you complete the shift from one gear to the next, up or down? Is it because of how rapidly/ slowly the engine's rpm changes? Because of the close ratio of the transmission gearing?
I understand there is a clutch break that is activated when the clutch is pushed to the floor. Is there anything that lets you know how far you can push the clutch in before activating the clutch break? Some kind of detent, or just a change in pedal pressure or something?
I know how an automobiles clutch and transmission work, I haven't had any experience with a tractor/ truck though. I can say that once I learned how the clutch worked in the automobiles, it made learning to drive them much easier. It took the mystery out of it. It wasn't just a "push in the magic pedal, shift into a gear, let the magic pedal out and away you go". I learned why I needed to let the clutch out slower or faster, and why I needed to accelerate more or less depending on conditions. I think it would help me and possibly some others if the magic was explained.
Questions about driving a truck/ tractor
Discussion in 'Questions From New Drivers' started by alone, Jun 27, 2014.
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Truck: carries its own load (pickup truck, straight truck, box truck)
Tractor: worthless without implements (trailer, thresher, etc).
Semi-trailer: semi-articulating trailer (there is load in front of the front pivot point -- the kingpin)
You double clutch because truck transmissions are not synchronized. Car transmissions have synchromesh that matches input/output shaft speeds as you shift so there is no grinding. With a truck you have to match input/output shaft speeds by rev-matching to avoid grinding. -
#1. "truck" CAN refer to the entire vehicle including trailer. "Tractor" is just the cab section.
#2. Double clutching is because 99% of tractors dont have a synchronizer (spelling?). That the bit the makes sure your gears are all spinning the same speed when you shift so you don't hear a loud crunch. Its a fragile part, and wont survive life in a truck. So we have to do it the old fashioned way.
#3. Not one of the 3 trucks I ran had any sort or detent or other obvious sign that you had hit the clutch brake. After a while you just kind of figured out where it was on the pedal stroke. The ONLY time you use it anyway is when your shifting into gear from neutral at a stop. Going up or down the rest of the time a small clutch depression is all thats needed. The clutch brake is only activated when you put the clutch to the floor.
Thats my best ""laymen's" description, and how ti was explained to me. -
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So to clarify, truck is the whole thing, tractor is just the tow vehical that doesn't have cargo.
Cars have syncroes that make the motor side and gear side spin at the same speed as you engage the gear. Trucks dont. By double clutching, you sync the speeds so you can slide it into gear. You can also float which basicaly is adjusting motor rpm perfectly to match the speeds on your own. Some single cluch out of gear and float in. Most truckers eventually learn to float to save their left leg. In some cases its hard to get it out of gear (like a steep uphill, or when its cold). that when i single cluch to nutral then float in. Cluctching to nutra then clutching again gives you more room for error getting it in the next gear. -
Double clutching is a useless as Satellite navigation on a Locomotive. I ahve never done it in 4.3 million miles. Drive like you have an egg under your foot. Drive a truck like its a loaded weapon and could go off at any time.
Follow that car, Godzilla - and step on it !"semi" retired Thanks this. -
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Semi comes from the fact that the trailer only has one set of wheels. It is a semi trailer not a full trailer.
Everything else has been covered.
A truck driver is the under paid over worked man who sits in the tractor. It is called a tractor because we all want to retire to a farm but our wives want to live in New York City.
Last edited by a moderator: May 9, 2015
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YOUR BOY E THE TRUCKER ( on you tube ) has a very good shifting video. you can find most anything on you tube.
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Last edited by a moderator: May 9, 2015
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