Double clutching

Practice! That's pretty much it...The timing will just fall out after alot of that! But, remember to just 'lightly' clutch, dont go too far down and wear out that clutch brake (also slows down the shift!) ...Good Luck...JAM

 

What he said, Listening to the engine/rpms may help also.

 

"double clutching?" why are you even using the clutch at all? what are you driving - a 1903 Stanley Steamer or something???

 

Day-um! Glad you aren't dring MY truck!

 

Our instructor told us to use the Adam's Family theme song to time your double clutching.........you clutch at the clicking of the fingers.

 

First of all you need to (and I'm not saying you haven't) do some research and see how these parts work and WHY you need to doubleclutch in the first place. It will make a lot more sense if you know why you are doing it an what is happening when you do it. You need to realize that this whole process is trying to match your road speed (mph) with your engine speed (rpm) using a transmission full of gears to match these together to stay at a proper mix to make the truck happy (as in running instead of tossing metal parts everywhere).

To match the road speed when there is none. you have to STOP the transmission from turning. when the truck is sitting there idling, the engine is moving, the transmission is moving and of course the wheels are stopped. So how do you get the transmission and the wheels to match? You have to push the clutch all the way to the floor to engage the clutch brake. This is the ONLY time that you will do this! So, you step on the clutch and wait a second or two and the engine in still moving, the transmission stops, and the wheels are now stopped. You may now place the transmission into a gear of your choice. When you slowly and smoothly release the clutch (yeah, its heavy) the engine is still moving, which contacts the clutch which starts the transmission moving which starts the wheels moving.. you are know synced up and moving down the road,,, but of course in the lower gears your max speed is less than 10 mph... you need to shift into higher gears to get that done..

The way I taught my students was to make believe that after the wheels started rolling that the clutch pedal was a hot iron. How do you check a hot iron? By quickly tapping it so you do not get burned! You TAP the clutch and only need to push it in a few inches. This is one of the most common problems for new people learning to double clutch. They usually have been driving cars and they have it ingrained in their skulls that they have to MASH the clutch to get it to work. In some cars, the harder you mash the clutch the better it works. This is completely backwards when you are talking truck clutches.

You have to get and keep everything moving in the drive train. the engine is turning, the transmission is turning and the wheels are turning, if you mash the clutch too far.. you engage the clutch brake and you now have a engine that is moving, wheels that are turning and a transmission that is slowed or even stopped, you have to get off the clutch to get things synced up again. All of this is happening while you are trying to steer and look out the window!

So you now know that you know that you have to tap the clutch to make it better.. but when do you tap the clutch? This is where study and practice comes it. We will use a generic number and say that the gears are 300 rpm away from each other. So if you want to UP shift, the rpm must DROP 300 rpm to get into the next HIGHER gear. Think of a staircase. Walking DOWN the stairs is like UP shifting. To get the truck into a higher gear, you raise the rpm in gear and gain road speed. At around 1000 rpm, you tap the clutch and move the shifter to neutral, as the rpm drops you tap the clutch and go to the next higher gear and release the clutch again. This is progressive shifting 101. You raise the rpm just a little higher for each shift. You do this until you are either out of gears, or at a speed in a gear that you can keep the engine in the "operating range".

I'll get into this a little more tomorrow.. I have to hit the floor early for a trip to Waco, TX.

See everyone tomorrow evening..

 

It was required by my company too, its a good habit, maybe not needed as much as it used to be due to hydraulic synchronized shifting, but still adds years to your tranny's life. I'll step aside and let Fozzy continue his lesson, its on the mark. You'll notice, when your timing is right, you barely need to direct the shifter towards the gear you want it in, you won't even need to push it in, the synchro will draw it in and all you have to do is give a little extra nudge to ensure its there.
I don't know your automobile experience, but I grew up with the Hurst shifters and big motors and was used to, as Fozzy says, jamming that clutch down and slamming that shifter into gear, neither method will get you anywhere with a truck transmission! Although the clutch is heavier, it is much softer. Back to Professor Fozzy!