Any tips for learning to shift without clutch

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Short explanation: Bring the motor up to the shift point, level off the RPM, put pressure on the shifter, then let off the throttle and move the stick to the next hole.

For downshifting, bring the motor down to the shift point (usually braking), put pressure on the shifter, tap the throttle to move it out of gear, then "push through" on the throttle to rev the motor up, and slide the stick into the next hole.

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Long explanation: The motor applies torque through the flywheel onto the clutch and into the transmission. This is a rotational force. This force is spinning the gears in the transmission, "transmitting" power to the rest of the drivetrain and road. You have to lower this force in order disengage the gears.

By "leveling off" the throttle at the shift point (i.e. CAT C-15 is 1500 RPM), the force holding the gears together drops substantially, allowing the shifting forks to slide the gears into the next position. Once the force is broken, the teeth of the gears are no longer "gripping" each other.

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I've trained about half a dozen brand new drivers how to float in 30-60 minutes. When I started, I had a problem learning how to do it and was shown the same training techniques I use today. It works every time.

Good floating comes with practice. You can't hesitate or be scared of grinding. It happens and you just have to try harder when you make a mistake. It's impossible to "tell" someone how to do it. I always have to show drivers how I do it for them to understand the process.

It took me about 6 months to get good enough to have a "clean day", or a day with no missed shifts. Then over a year to get to the point where I would consider myself a "smooth operator". I'm still teaching myself new things and getting smoother as days go by. This spring I taught myself how to shift with the Jake switch on, but without engaging the Jakes, from 1st to 18th and back down.

Not getting discouraged is a big part of success.

 

The transmission is designed to be shifted without the clutch, it is actually easier once you understand what is happening.

Each gear in the transmission is a set ratio change from the previous and next gear, the amount of change is revealed by your tachometer as you run up through the gears and down through the gears.

To determine the rpm "split" between the gears just set your speed at a steady 50 and observe your rpm's, then upshift one gear and again hold a steady 50 mph speed; observe the tach again and the rpm's will be lower.

The difference in rpm between the two gears at the same road speed is how far apart the "splits" are in your transmission.

What that information is telling you is when the transmission is lined up to catch or drop a gear.

If you determine that your transmission has 600 rpm "splits" (most 10 speeds) then you know that up shifting when your rpm's reach 1900 will mean the engine rpm will have to fall to 1300 to enter the next gear smoothly, if your rpm's drop too far or not enough you will have to grind/force the transmission into the next gear.

Likewise when downshifting, if you drop a gear at 1300 rpm you need to raise the rpm to 1900 in order to enter the next lower gear clean, revving the engine too high or not high enough will result in grinding as you force the shift.

Remember that road speed is part of this equation, if you are going uphill your road speed is falling quickly so a transmission with a 600 rpm split will line up at less than a 600 rpm increase when downshifting on a pull, how much less will be determined by how quickly you can adjust your rpm and make the shift; if you are very good the road speed factor will only change 100 rpm or so but I know guys that are so slow they drop 2 gears at time to buy enough time to shift clean. That is fine, you will get faster with practice and not have to skip gears when downshifting over time.

When up shifting on a grade the same applies, the road speed decreases more than when you are on flat ground. That means your rpm will have drop a little more than the 600 rpm to account for the decreasing road speed; you shift a little slower.

Using the clutch interrupts the road speed/engine rpm relationship, this forces the clutch you reestablish the relationship after every shift (hard on clutches and drive train components) and it pretty much insures that driver will never become acclamated with the transmission.

The clutch is designed for stopping and starting, they last forever when used this way so you are right in wanting to learn the proper shifting procedure.

Once you understand what is happening you will know exactly what you did wrong when you grind a gear, as you make adjustments that correct the problem your mind and hand will memorize the sound and timing in all the various situations; you will be shifting without nicking a gear while not even thinking about it.

Good luck and stay with it, too many guys just quit trying or have no interest in even learning how to shift correctly!

 

Yes, they are called automatics.

 

I hear people all the time who claim to be experts and boast about how they can change without the clutch, however if they were such experts they would also know about the potential damage they are causing to their gear box talk to any expert engineer at Eaton Fuller about it if you don't believe me. One of the prime reasons alot of transport companies are going to Auto gear boxes is the huge expense of having to repair and replace trashed gear boxes.

 

The clutch pedal is there for a reason other than a foot rest!

 

Be vewy vewy cawefull....

 

When you normally would double clutch up shift or downshift. Just confidence.

 

Gearboxes are destroyed by drivers shifting into gears at the wrong rpm for the road speed and gear choice, using the clutch makes this an easy and common error.

It is a fact that non synchronized transmissions are designed to be shifted without the clutch, if someone is too lazy to learn how then that is their business (and the business of whoever has to pay for the repairs) but there is no mechanical justification for pushing the clutch after the truck is in motion.