Need extra SEAT TIME? Learning > Texas

Did you ask the school ?

 

Find the "sweet spot" rpm for that truck.

 

It takes practice. Once you get past the school and test stuff , you can just float the gears. MUCH easier. Best of Luck.

 

Like @cuzzin it said, school is your best option. Pay for extra time if necessary. I've seen a place in Amarillo that rents trucks for CDL testing, but not extra time. Since you aren't licensed you may not be able to be insured by some random truck owner that doesn't hire newbies. NOBODY I knew felt ready for the CDL test, all but 3 of us passed out of 30.

You may be puching the clutch too deep. 99.99% of rookies do that. If you push the clutch more than 1/3-1/2 down you engage the clutch break. Clutch brakes slows the RPMs and if you slowly double clutch your road speed and RPMs are no longer close enough to shift so you just grind gears.

Try just barely pushing the clutch pedal. Press just enough to pull gear lever out of gear. Press the clutch pedal about that same amount to get into gear. You should NEVER have to pull or push on the gear lever with any strength. Use as much force as you would move a full coffee cup. EVERY newbie I've seen pushes the clutch fully to the floor and grinds and grinds and grinds. A truck clutch DOES NOT OPERATE like a clutch in a 4-wheeler or motorcycle. For those other vehicles the clutch is ALWAYS fully down or fully up except for a nanosecond in-between. If you have clutch experience before trucking I can guarantee that is your problem.

 

Too may people take the "double" part of double-clutching too seriously. All the extra clutch pushing is simply a timing exercise, an amount of time elapsing from when you leave one cog until the next cog slows down to the same speed that your output shaft is at. I tried it for about an hour, and never did it again; I just remembered the amount of time needed. Push in the clutch (and NOT all the way to the floor, because THAT hits the clutch brake and you'll NEVER get into the next gear), wait in neutral, then slip into the next gear.

 

Times have changed.

1990 me - “You care if I float ‘em?”

1990 examiner - “Do it however you want.”

 

Double clutching is not difficult. Tap the clutch in just before moving the lever out of gear then again before dropping it into the next gear. I never double clutched in 25+ years of trucking but I did at truck driving school. Could do it right now like nothing. It aint difficult don't overthink it.

 

Did they teach you or you can try the way I was trained to shift gears. You shift low rang gears at 1,000 rpm. You do this for a couple reasons. One is you don’t have to be any good at double clutching. It also stops the truck from rocking left and right. You don’t need 400 hp or 500 hp to get truck rolling at stop lights and signs.

You will go thru 5 or 6 gears from stoped at light to get going and thru light. That’s how fast you will shift gears, but it will be almost smooth at butter. Ha ha

when you flip the switch to high range you can bring engine up to 1600 rpm. Then shift gears and take little time like 1 second and let rpm drop to 1200 rpm. It should go into gear.

The thing people don’t seem to say is how most trucks have 400 rpm step between gears. 1600-400 is 1200. If you shift to fast gears will grind and if your to slow you will miss the 1200 rpm and gears will grind.

You can change those number for the new engines like 1400rpm and 1000 rpm because the newer engines can pull at 1000 rpm. The older Detroit S60 and N14 had most pulling power at 1200 rom

 

What Brandt is talking about is called Progressive Shifting. There is rarely any need to rev the bejezus out of your diesel getting off the line; shift quickly into higher gears (depending on your load and incline) without skip-shifting, then rev a bit higher as you go into the highest gears. This strategy is best for engine longevity and fuel economy.