Double-clutching, Downshifting And Struggling...

I am currently in CDL school, I have 3 more days of training and I test on Monday. I am really struggling with downshifting. I have read the tips on adding the speed numbers to equal the gear tip (2+5=7th gear). We are in a 99 International Eagle with a Eaton 10 sp. I think it's been pretty beat up from students and we actually had to have the clutch adjusted yesterday during class. Today another student was jammin' and crammin' because she was struggling and so she was angry, popping the clutch and grinding. I drove after her and struggled to downshift into lower gears. The instructor then drove and had some difficulty also. When we got back to the yard, another instructor drove it and said it was fine, it was all me. I have been having issues with the road speed and trying to get that down, but I am hoping I might get some good tips here.

Thank you!

The easiest way I can explain downshifting is to point out that its all about the RPM's of the engine. It will vary with each transmission slightly but typically the truck will shift out of gear about 300 to 400 RPM higher or lower than it goes into gear, depending on upshifting or downshifting. Let me give you an example:

When going UP the gears most transmissions will go out of gear around 1300 RPM then go into next gear around 1000 RPM. This is known as the RPM spread and most transmissions have about a 300-400 RPM spread between gears. So knowing that to DOWNshift you will need to give a tap on the throttle to bring your RPM's up to get the lower gear. So lets say your in 10th gear and slowing down. Around 45 MPH you will need to shift down to 9th. At that speed your RPM's should be around 900-1000 RPM. So when you need to downshift, while doing your double clutch you should quickly tap the accelerator up to 1300-1400 RPM to get the lower gear. (This is why it's so much easier to "float" gears than double clutch. Floating means you don't use the clutch at all to shift. Its easier on the clutch and much easier to do when you get the hang of it)

When you are giving throttle to bring up the RPM's, it should be a very quick tap on the accelerator and you should only have to push it about 1/4 to 1/2 of the way down. Next time your in the truck, before you start driving practice tapping the accelerator to see how far down you'll need to push it to get the desired 300-400 RPM you'll need to get the lower gear. Also when your going UP the gears pay attention to what RPM you're at when the truck goes into gear. This will give you an idea of the RPM spread of that transmission.

So here's the bottom line. To get the next gear down just tap on the accelerator to bring the engine up to 1300-1400 RPM and you should be able to get the lower gear.

I hope this helps in some way. If not can I get an A for effort?

Thank you so much for your reply! Yes, I understand the RPMs and how they synch with the shifting....it's getting that rhythm down I'm having problems with, I think. And road speed. I slow down and then end up going too slow. I just had a really awful day.

And you get an A... awesome explanation!

Just one more thing...

How long are most CDL schools? This one is 2 weeks, with only about 8 hrs of actual drive time and about 8 hrs for skills...

Just one more thing...

How long are most CDL schools? This one is 2 weeks, with only about 8 hrs of actual drive time and about 8 hrs for skills...

Mine was 4 weeks 1st week classroom and permit testing. 2nd-4th was working at learning to drive, back, basic handling and double clutching before licence testing. For me, everything I learned in school was just to pass the licence test, have found with my trainer that i am relearning how to drive again, for the second time.

The way I've always taught people is that there are 3 RPM windows you'll deal with, a level ground window, a down hill window and an uphill window. Level ground is right around 500 RPM's, going down hill the truck will speed up when you pop it in nuteral so it will stretch to 750 RPM's. Going up hill it's smaller because you'll slow down, that's right around 250 RPM's. As stated earlier, these are generalized windows, each truck will be different, sometimes it helps to count while on level ground, like one-thousand-and-one as soon as you get it in neutral then push it back in. Don't take off in low when your empty, start in second. Also, if you find your self on a steep uphill loaded and stopped, you can feather the clutch just like a car, the increased resistance will negate the high torque. If the hill is steep enough and you try to fully engage before applying throttle, it will kill the motor every time.

Michelle, double clutching is tricky for every one when they are first exposed to it. You got some good advice from everyone - just hang in there and keep practicing as much as you can.

The length of your school kind of concerns me because most of the jobs available to a new driver are going to require a training certificate showing that you have received 160 hours of training, which is impossible to achieve in two weeks, unless they are holding class on Saturday and Sunday also.

Is this a private school, or a company sponsored training program?

If it is a private school do they offer job placement assistance?

Hey there again Michelle. Old School brings up a very valid concern. 80 hour school time is usually a cdl "refresher". I took an 80 course to get recertified on my already existing cdl. To start from scratch usually requires 160 hour school. Talk with your school asap before you graduate.

Today was a much better day and I did much much better on my downshifting. Thank you for all the help!

I asked around and I am in the better school here, but it is only 2 weeks of school. I had to have my permit and my DOT physical already before they would get me in. It is a private school and I am actually going to drive for my son-in-law, he has his own company, so I won't need a training certificate. I totally understand that I am by no means experienced, qualified, etc. to do much more than drive the trucks, but he is willing to train me and get me going. I will be hauling water from oil wells to dumps, so of course, I have my tanker endorsement. I have driven (with permit) and worked with him before doing this same work, so it's not unfamiliar.

After reading a few threads on here, I think WY is not as stringent on their regulations as other states. Our biggest problem here is getting good reliable people who can pass a drug test and truly want to work!