Panic situations/Downshifting

Mack trannys can be a pain, they have a shorter space to shift at when you reach the right RMPS. Practice and Planning is the KEY!
Figure your distance for stops and turns without down shifting at all, period. Then you'll have control of that and stop worrying about the shifting.

So this is what I suggest go behind a big shopping center closed plant something with some ROOM, and practice there. start in 1st and go thru the gears until its time to go split to the high side. then back off the fuel and let the RPMs and speed drop just barely put a little bit of pressure on the shifter don't grind the gears or force it! It'll slide in when the RMPs are right.
Practice in the LOW SIDE until you get the hang of it. Listen to the engine keep the RMPS LOW no need to wind it up till it's screaming!
The high side works the same way. Practice backing up there. Pick an object that you want to back up to, then back up AFTER you make sure that there is nothing behind you to hit. ALWAYS when in doubt get your butt out and LOOK. 99.9 % of all backing accidents are preventable.
Listen to and feel the truck engine and it will TELL you when.

Rule of thumb I told students. low side is road speeds below 20 mph, everything else is high side of the trannys.
Plan the stops and turns. Since you are hauling liquid assuming you have a smooth bore tank ( no Baffles) remember when you DO stop it's going to give you a little push when the liquid rolls back to the front of the trailer, that alone can move you into an intersection thru a stop sign on into the rear of a vehicle in front of you. KEEP your foot on the brake!!
Turns, the liquids rolls the opposite way of the turn, then rolls back when you get straightened out.
To get a visual of what's going on in the tanker:Take a half a bottle of water and lay it down length wise slide it on the surface then stop moving it watch the water and what it does. Thats what's going on in the tanker.
It doesn't matter about the peeps behind you, they should have left earlier. DO not worry about them it's the stuff in front that you need to be concerned with. Always plan to make the stops and turns slower than everyone else, you are not driving a car so don't try to drive it like one.
Stopping empty is in some ways harder than when you are loaded! Why? Because the braking system is designed to stop the truck with a load, most newer trucks have a device built in to adjust the braking power automatically when you are empty, called a brake power limiting device it works in the back round you don't do a thing. BUT you have to remember to allow the ROOM to stop period.

 

Driving a truck is a lot easier when you slow things down. When downshifting, remember to slow down. You've got to match the RPM with the speed of the truck. Slowly apply the brakes, allow the truck to slow, then downshift. If you miss the gear, slow down some more, then try again. Remember to stay off the throttle after you downshift. I've seen several drivers downshift to slow down, then for some reason they apply throttle! Why downshift, if you don't plan to slow down or if your trying to apex a hill? Just remember, you are new and you're going to make mistakes. So don't be so hard on yourself. Be patient and keep your chin up. Your boss hired you because he saw potential in you. Now if he took a chance on you; why can't you take a chance on you too?! Good Luck!

 

I use two approaches.
To slow down........Clutch it and move to neutral. Then goose & release the accelerator, and slide it into gear the lower gear. I don't use the clutch for the downshift itself, just to get into neutral.

Crawling slower and slower, like in parking lots or maybe a stop light with lots of room in front of me...........I'll let the truck idle slower and when it is about to lug, I put in neutral (use the clutch) and gently increase the RPM. Gently. Then press the gearshift into the lower gear. Press, not jam. You be able to feel the gears bumping and adjust your throttle accordingly. And best of all, the observer is barely able to tell that you have downshifted - it's that smooth.

Use technique #2 when you approach a stoplight at the top of a hill. The truck will stop itself, right? You just follow along.

 

This is really an interesting thread to me -- these trucks obviously shift very different than my little five-speed Subaru!

Am I reading this right? You depress the clutch, shift into neutral, release the clutch, then depress the clutch again to downshift into the next lower gear? Is it safe for me to assume this is "double-clutching"?

I am learning so much here!

 

Yes this is double-clutching,if thats how you shift. Me personally I float the gears,but for a newb. IMO you should learn the proper way to shift before attempting to float thats why I didn't explain it that way.

 

Thanks, mikroos! Obviously, I'm not a trucker, nor am I a trucker-in-training. At best, I am simply a happy road traveler when time and money permit. But I count a few truckers among my friends, and it's nice being able to understand at least some of their language.

And you know something? The more I learn, the more I find myself WANTING to learn even more... LOL

 

your welcome,but just remember trucking is a sickness once you get it in your blood you cant get it out :smt044

 

i used to "float" the gears on my motorcycle. except there was nothing smooth about it. snatch the shifter up at the top of the powerband.....GONE

so, they teach you formally to double clutch it?
so i shouldn't "float" any time at all when training at school? what about with trainer?

 

Every trainer is diffrent but when i was a trainer i wouldn't let you float until you first could prove to me that you could double-clutch,up and down.

 

i kinda figured it was a preference with the trainers.