I am possibly the worlds worst double clutcher!

I suck at double clutching as well. I rarely use my clutch once the truck is rolling. You have to master it enough to pass the test I suppose but beyond that, learn to shift without the clutch and your life will be a lot simpler.

 

Relax, yer prolly over-revving the engine and trying to rush it. 1400-1500,Let off,clutch in justa lil,to neutral, clutch in a lil goto higher gear at about 1000-1100. Take your time,its not a race,tranny has big gears and teeth. Works the same for a downshift,reverse the #'s.

 

The double clutch is a very shallow depression of the clutch. Cranking is a deep depression. The stroke is shallow and quick. Much shallower than you'd think.

 

I am in the same boat as you. First day driving on the street. I don't know how hamburger I ground up today. Instructor was great and patient. He said it's about all about timing and RPM's.

 

Lookie here Bucko, I hate to have to tell you this, but you ain't been around long enough to be the world's worst double clutcher. You gots to have years and years of experience behind you before you qualify for that title!

You've been given some good advice here, so all I will say is relax a bit. It will come with a bit more experience. Oh and one other thing, drivers who have been doing it for many, many years, will still occasionally grind gears. But not to worry, I hear they will be making gears out of jello next year. . .

 

The engine type makes a big difference in the speed of your shifting. If you are running a Cummins, you shift fairly slowly, if you are running a Detroit, you have to be a little quicker. It takes practice to be able to get the timing right, but if you keep at it, you will get it. Driving is not rocket science, it is about practice and common sense.

 

It'll take you a week or two to start getting use to it. There is no rushing it and you'll be missing gears and stuff for 6-12 months. Even then you'll have an occasional goof.

I don't know what they taught you so far but you need an understanding how an 18 wheeler differs from a car. Imagine two gears spinning different speeds and you want to mesh them together. It's not going to work because they are spinning different speeds. Cars remedy the situation with thin brass rings in front of each gear called synchronizers. They just have a few teeth on them spread far apart. They are designed so two different speed spinning gears can mesh without grinding. It's Kind of a pre-mesh to get the gears spinning the same speed.

Now a big truck doesn't use synchronizers because they are fragile brass rings that can shatter from extreme torque and weight of a big truck. That's where double clutching comes into play. The concept is to get gear driven by the engine spinning the same speed with the other gear that is connected to the rear end through the drive line. That's why you hear match your engine speed with your road speed.

You control your engine speed by revving the motor or taking your foot off the throttle. Road speed is controlled by your present coasting when out of gear. That's where hills can come into play. Go up hill and you'll slow down. Go down hill and gravity will make you speed up. Hence changing how fast the other gear in the transmission spins.

Here's the double clutch in slow motion...
Clutch in, allows you to pull the two gears apart with the shifter
Clutch out let's you adjust your engine speed to match your road speed gear
Clutch in allows you to move the two gears together because they are now spinning the same speed.
Clutch out you are now connected engine to rear end.
rinse and repeat through each gear.

Note going up hill your gear to the rear end will slow down quicker so you won't bump your engine up as much. Going down hill you should be in the right gear but if you do have to upshift gravity will make that rear gear spin quicker while you are out of gear. Hence you will shift quicker.

Trucks vary by engine size and horsepower. Smaller engines you will wind out a little farther. As you get better at shifting you will learn progressive shifting. That is pretty much getting the most out of your engine without wasting extra fuel from over revving and dropping below peak torque of an engine. You know how to work your engine. RPMs waste fuel, peak torquing the engine doesn't. In other words like a Cummings engine will work it's best at 1200 rpms before it starts losing power. So you want to keep your shifting as close to that rpm you possibly can. I wouldn't worry about that stuff right now because you have to learn the very basics first and as time goes on you'll get more knowledgeable and experienced. Eventually you get good enough at shifting you won't even think about it. You can function by sound. You'll be able to float the gears eliminating a lot of wear on the clutch and your leg. But get double clutching down first or you'll create extra wear on the transmission and mechanics get mad. For now watch that tach and speedometer and the road all together.

Your shifts will get tighter in time and just for learning purposes, upshifting try coming out of gear at 1600 rpms and back in the next gear by 1000. Downshifting just the opposite, either hitting a hill or braking come out at 1000, bump the engine to 1600 and clutch back out. Double downshifting drop close to 700 rpm, first clutch, bump to 1600, clutch in and drop two gears, clutch out.

Be smooth, don't rush it and feel you have to do the quickest motion of double clutching possible and be shifting faster than the engine rpm can drop. The same with downshifting in the middle of your double clutch new drivers tend to over rev the motor. Again don't shift faster than the truck. First clutch, gears apart, light bump close to 1600 and the gears will be pretty close to meshing.

When you start getting the idea of shifting start paying attention to your speedometer too and compare your road speed to what gear you are in. What gear was I in when I made that turn? What gear was I in when I gone this fast? Then if you ever lose it you'll have an idea what gear you should be in.

Be patient, it'll come to you. A couple months from now you'll be shifting well enough to be on your own and be able to correct your own mistakes. Until then you'll have someone beside you hopefully helping you.

 

If you can't find them grind them. Everybody is a great shifter when nobody is in the truck with them. As soon as somebody gets in the passenger seat the gears seem to grind by themselves. Lol. It just takes practice.