Droopy's trucking fact of the day.

[Droopy]

Big trucks have lots of gears in their transmissions and if you like to do some gear jamming this can be on of the cooler aspects to driving a truck. The most common transmissions are 9, 10, 13, and 18 speed manuals with automatic, 7, an 15 speeds available, but less common. I've just driven 9 and 10 speeds in my career so I will tell you how those work.

The transmission in a big truck does not have a slot for every gear. The slots are shared by gears. For example a 9 speed transmission works this way. The first five gears work like a regular five speed with a slot for each one. After you've peaked out on fifth gear you flip a little lever up on the gear shifter known as a range selector and then shift to where 2nd gear was. Only it's not 2nd gear any more it's 6th because you have changed the range on the transmission. Likewise where 3rd gear was is now 7th and so on. After you reach 6th gear, the transmission is like a four speed and you work through the gears up to ninth. A standard 10 speed works pretty much the same way just with an extra gear.

The truck I drive has a transmission called a Super 10. It works differently than a standard ten speed. You have five slots and in each slot is two gears like a reagular ten speed, but instead of a range selector it has something called a splittier on the side of the shifter. In gear slot one is 1st and 2nd gear. In gear slot two is 3rd and 4th and so on. It works like this. You start off in 1st gear with the splitter in the back position. Once it's time to switch gears you flip the splitter forward, let off the gas and the transmission shifts into 2nd gear. After you've reached the top of 2nd gear, you flip the splitter into the back position and shift into the second slot for 3rd gear and so on.

When you shift gears from one slot to the next you are supposed to double clutch a big truck. This means that you have to press in the clutch coming out of the gear, let off, and then press in the clutch going into the next gear. There is a way to shift trucks without using the clutch. You just have to have good timing. That's the way I shift and I only use the clutch for stopping and starting. When the gear reaches the top of it's range the gear shifter will slide out of it's slot pretty easy. Then it's just a matter of timing the RPM to get the gear to go into the next slot. It will slide right in if your timing is good. If not you'll grind the gear. Some drivers choose to use the clutch even if they know how to float shift. When I asked my first driving instructor if he'd teach me how to float shift he told me that the clutch was there for a reason so use it. I had to learn how to do it on my own. It took me a couple of months but I finally got the hang of it.

[Droopy]

1. kick

Okay, everybody, you can start posting to my thread now. :)

[KG]

2. i'll try to keep this in mind next time i drive a big rig....

which would be the first time i drove a big rig. (they call 'em big rigs?, not hip to trucker lingo, i only know one OTR driver...)

[KG]

3. also, this shifting thing seems a little complicated, tho i'm

sure it get easy after some practice, but did you ever notice in action movies how characters seem to just hop into the cab and take off?

[Droopy]

4. Shifting is one of the hardest things to learn

As far as driving a big truck goes. It takes some time to master it. The hardest thing to learn to do is backing up. That really takes a lot of practice to be able to do properly. There are so many different situations as far as backing goes.