going up a mountain shifting?

I suspect the OP is driving a newer Freightliner. The clutch switch design is crap. The switch doesn't actuate till well past the point the clutch starts slipping.

 

My old truck (1st Gen Cascadia) was like that as well, had to nearly push the clutch in to disengage. The method I used, because my steering wheel was equipped, was the "cancel" button. Makes things a bit easier..

 

Wouldn't watching the road ahead and paying attention to your surroundings get rid of the problem of the cruise control. I mean grades that are steep enough to require you to down-shift don't exactly sneak-up on you. If a driver is watching his gauges / listening to his engine , he knows that he's begging to climb a hill. IMHO...( never did use cruise too much , didn't feel in control) once you see that the truck is begging to pull , you cut the cruise off , and get ready to down shift....you don't wait til it's too late.

 

Don't shift going up a grade?????????? Get in a low gear before going up????????????? You use the momentum you have built up on the flat before the grade to start up the hill and down shift as needed until you reach a happy speed with a happy gear for your weight. Why waste momentum/fuel slowing before an uphill grade? Someone is confusing going up verses going down. I agree that a driver should know how to get things back under control if shifting going down, these trucks have been known to jump out of gear and what you gonna do? scream and ride it to the bottom?

 

Hi pattyj, WHEW, tough crowd, hey. I think I know what you mean.

 

Also need to cut the cruise control off when you start up or down a mountain. That's what sounds like is happening?

 

Actually, with larger engines, that's not always the safest thing to do either. The safest rule of thumb to follow is to go down the mountain in a gear that will hold you at or under the posted speed limit without over-revving the engine. To do that, you have to learn your trucks rpms for each gear as compared to the max speed of each gear. For instance, how fast are you going in 9th when your rpms is completely on the top side? How fast are you going in 4th gear when your rpms are maxed? Etc. Never shift going down a steep grade though. Once you have learned the info above, you will know what gear you need to hold the truck in going down the grade, make sure its in that gear before you go down the grade. Most trucks now have Jake Brakes that use that basic principle to hold the truck back which helps a lot. The first 20 or so years of my trucking, I never drove a truck that had Jakes. That's how I came up with that formula and it always kept me from burning my brakes up, even on grades like Donner Pass, The Grapevine, Monteagle (which is tame now compared to 20 or 30 years ago) and other infamous grades. Basically combine your speed, your rpms and the speed limit into one working plan of action. Always worked for me.

Obviously, based on what you're hauling, you might not feel safe running the speed limit down a particular grade but that's something you have to decide on before you start down the hill. Experience will teach that to you.

 

Practice... what's that? If you still need practice, why would a state grant a CDL?

Downgrade downshifting is an essential skill to skill to have, but avoid the need for. It's best to learn/practice that near the very bottom of grades, traffic permitting.

 

Not saying that Jason is doing it wrong, because his technique apparently works for him. This is for you new guys. Climbing a hill will drop the rpms faster than downhill and flat land. You all know this. There's something you can do to lessen the chance of missing a shift. Jason says that he changes his gear at 1100 rpm. If you are climbing, and the rpms drop too low, your chance of missing a gear increases. Why? Because you have to blip the throttle to match the engine speed with the tranny to get it to drop into gear. Instead of waiting til you get to 1100 or 1000 rpm, try it at 1250. If you drop too low, 900-1000 rpm, with the truck slowing quickly, it will take an incredibly accurate shift to get it into gear. More than likely, you will hear a bang and a crunch and miss the gear. A 1250 shift, rev to 1600, and let the revs fall should allow a much smoother and easier downshift. I hope I am making sense.

One more thing. I think I read a pamphlet about how the newer engines were made to be lugged around at extremely low rpm. Well, I don't see how that will work without cooking your motor. I mean manufacturers brag about their engines and all, but from everything I've seen the EGTs will get so hot that you burn your rings and pistons. And you see them, 3/4 of the way up the mountain, with blue and white smoke pouring out the exhaust. I don't have a new engine, but I imagine that with all the stuff they have between the turbo and the emissions stuff, they should superheat too if you lug them up a long pull.

 

Hey 70s_driver, once when coming back from Fla. I took 41 down the backside of Monteagle, 2 lane, that scared me in a car!