Please need help (downshifting)

99% of fly by night schools that got one from the scrapheap, detailed and painted it?

 

Yes, and no. I understand why everyone is telling you speed doesn't matter, but at the same time, if you're trying to put it into a gear that's too low for your speed, the rpm needed to get it into that gear will be too high and you'll never get it in. If you're skipping several gears, it's harder to know which gear is appropriate just based on rpm. I'm no manual shifting expert, but I did recently learn manual in cdl school and was at least proficient enough to pass the road test. It takes practice and experimentation. I just drove the truck around the yard practicing the upshifts and downshifts and figuring out what worked and what didn't.

 

^ that's all the info you need right there. Now stop asking the same question.

 

Your question is kind of vague, like "are white cars fast?" Your speed will determine what gear you should be in. I have read recently a formula that some drivers use is that at 5, 15, 25, 35, 45, 55, you add both numbers together, and that's what gear you should be in. I suppose with average truck gearing, for a 10 speed, that may be true, but tire size and rear-end ratio do vary.

A truck is not a car. Except with a Jake on, a diesel engine does not provide much braking like you would find in a car. A long off ramp, there is no point in constantly downshifting through the gears. Just push in the clutch when the road speed is too slow for the gear you're in.

If you're downshifting because of hill, it really needs practice until you have the feel of what gear and what rpm you need to be for the speed.

 

But don't do this on your road test. Coasting with the clutch in for more than the length of the tractor and trailer is an automatic fail.

 

ask the mechanic to go into computer and remove fuel governer. that way you can downshift from 10 to 5 to meet your demands

 

I'm sure it's his instructor telling him to make these large downshifts to minimize the amount of downshifting needed for the road test when the students really aren't that good at it yet. Mine did the same thing. Coming off the highway to a stop we were told to go from 10 directly to 6th at 20-25mph. Then stay in 6th until you come to a stop. I found it much easier to just downshift each gear at the proper rpm without skipping. In our trucks I felt like 25 was still a little too fast for 6th gear which made it hard to get in, but 10th gear was really struggling to go any lower. It's easier to just tell someone to shift at a certain speed than to teach them how shifting really works in relation to rpm and speed. Fortunately, I had watched a lot of Youtube videos on shifting before going to school.

 

10th gear at 650 rpm can get you into 8th at around 1500 rpm. So yes 2 gears is possible.

shifting correlates with rpm. 400rpm drop up shift, 400 rpm increase you down shift.

 

I suppose you're right. I got my license before CDL and even though I had to take it because I live in a state that requires it, my tester knew I had 15 years of experience and 30 years of having my license. He enjoyed going for a ride with someone who knows how to drive.

I was giving driving advice rather than testing advice.