Shifting

its all about knowing how fast your speed should be in each gear....once your speed is well below the gear you are in, take it out of that gear, rev the engine to match the tranny speed with your rpm, and set it in.

 

That is good advice. Our instructor is a woman so she should know. She didn't explain it like you did though. She said use your fingers because when you use your whole hand you have a tendancy to try and force it in and you can't feel it.

 

it is good advice...i never was taught to do it that way but i did figure it out, lol

 

Just watched this EATON vid on the Super 10.
I have to agree this looks very intuitive.

http://www.youtube.com/watch?v=V_cUUOFiPFU

 

No worries. Class 8 truck transmissions are all alike. Their only differences are the driver interface---the gear positions (the "pattern"), and whether or not they have a splitter. Once you understand what the range selector does, and how and what a splitter does, the rest is easy. The hard part is controlling and coordinating the clutch with the changes themselves, not where the gears are in the pattern or the widget used to select them.

Any trucker who has driven a while can handle any transmission in just a few minutes, even if he's never seen or used it before. A Super 10 is just the high range of a 13 or 18 speed, for example. And a straight 10 is just a 13 or 18 without a splitter. Etc.

 

Much of it is mental. Downshifting is the exact opposite of upshifting. Somewhere in your training the instructor should have mentioned that in order to make good shifts up or down you need to realize that three things have to be correct for each other. They are gear selection, rpm and speed. If any of these three is wrong for the other two, then your shifting will suffer. Anyone who believes you have to shift up or down at any particular RPM has not yet figured this out and "mastered" shifting.

Realize first that that the way I will explain this will be considering that you are on a level road. Once you can do this on a level road then the variables involved with hills (Up or down) can be added and it will make sense (Because hills change the speed of the truck therefore the rpm's needed).

A truck is what it is and you cannot change this so you must conform to what it is and what it needs. To do this you must realize that a particular engine has it's own fall rate, and (for a lack of a better way of saying it) there is an rpm difference between gears. For instance if I am going 5 mph in first gear at 1700 rpm's and I shift to second gear and I am still going 5 mph in second what's the rpm in second? Whatever it is, that's the rpm difference between gears. Let's say in second it's 1400. That means there is a 300 rpm difference between the gears. So if I want to down shift back to first from second at 5 mph and 1400 rpm I shift to neutral raise the rpm's 300 back to 1700 and slip it back in first.

You can make an upshift from any rpm as long as it can fall the amount of this difference. In other words if the engine idles at 600 rpms, and I am driving in a gear at 900, I can make the upshift by going to neutral and letting it fall to 600 and make the shift (Note I am not telling you to shift here, just that the shift can be made). To make the downshift I would hit neutral and raise the rpm's from the 600 back to 900 and make the shift.

Downshifting as upshifting is predictable. Depending on the max rpm's of the engine and the rpm difference between gears you can downshift 2, 3, and sometimes 4 gears based on rpms. For instance if my max rpm's is 1800, and a 300 rpm difference between gears, to downshift one gear I would bring my speed down until my rpm's were at 1500 hit neutral, raise rpm's back to 1800 and make the DS. For a 2 gear DS, I would bring my speed down until the rpm's were at 1200 hit neutral, raise rpm's to 1800 and make the DS. For a 3 gear DS, bring rpm's down to 900, hit neutral and raise them to 1800 and make the DS. These are examples, and generally you do not want to work around the redline of the engine as a slight increase in vehicle speed while attempting a downshift at engine max may make the DS not possible.

Generally when I have a student with DS problems I do two things after talking with him. Parked in a lot I have him raise and lower rpm's to where I say for a half an hour or so and then I blindfold him and expect the same results. I then put him on the highway at 55 mph and have him up and downshift from 7 to 8 and 8 to 7 (9 speed) as many times as he can for about 50 miles, up to about 700 shifts. Then we work on the other gears. Eventually one figures out that the brains of the shifting operation is his right foot. Train the right foot and shifting gets a lot easier. You can also work from speed also, but eventually you will work off of rpm, speed, sound feel, gut, memory and anything else you can think of. Don't limit yourself.

After level road work is good, then go work the hills. Take your time, relax, enjoy the truck and become one with it. BTW, on upshifts, if done correctly the vehicle will gain a little speed between gears on a level road and the rpm difference between gears effectively will be a little less than normal.

Best Regards

 

THEN do you take his blindfold off?

 

Sure! That is until he backs up again.

Best Regards

 

I float the gears in the super 10 that i drive, is this better than double clutching?

 

Most new drivers will over rev on a downshift and catch the rpm's on the way down.

Just give the accelerator a simple bump up and it is much smoother.

99.9% of drivers will match engine speed to road speed on the downshift. I did meet one guy that was backwards and matched road speed with engine speed on the downshift. Out of gear, he would hold the rpms steady at 1500-1600 and left foot brake. As the truck slowed he would slide it in gear at the sweet spot. Not recommended to left brake but his way was smooth too and interesting to watch.