FIRST 4 GEARS

Is it a fast grinding sound or a slow grinding sound? If it's a slow sound then the engine rpms are too low, you missed it, bump the throttle and try again. if it's fast, then wait half a second and try again, and again. you will get the feel for it, try not to think about it too much. Your subconscious will figure it out faster if you don't get in it's way.

 

Personally I find double clutching on the low side works best for me. I just pretend I'm cruising around and listening to ZZ Top lol. I don't buy into that you're not a driver unless you float every gear bull####.

 

Floating has it's place.

I consider it a tool when in battle and for whatever reason usually the pavement or load I might float a gear here and there. I just don't make a habit of it.

I do not float so I can sit and brag that I taught God how to float. That's not what it's for.

 

When I trained a guy once, he couldn’t shift the low range gears well at all. And, I can here guys next to me when we leave the stop sign or light with the same problem.
If you have a 9, 18, or 13, when loaded, I don’t count low as first, just FYI, start in first;if you’re light or empty, start in second; bobtail, start in third unless the grade dictates otherwise.
Once you’re going through the gears don’t worry about the tach. Use your ears and you’ll do much better.
The main reason the student I had couldn’t do it and why I hear so many guys jamming gears starting from a stop, is too much throttle. The point of low range is to get the truck moving and high range is for accelerating. Back off the throttle and it will do fine.
The loaded example is the best one to use. From first to second takes very little fuel and rpms and you should be able to go straight in, smoothly with no delay; from second to third, use a slight delay as you would in the high range and just listen to the motor.
Depending how heavy you are or if it’s a slight upslope you need more rpm. The sound of the motor will tell you when. Repeat until high range.
The key is not trying not to accelerate but get moving smoothly, after that, drive it like you want. For 80k and less, there’s no need to split low range.
Once I got the student to get his foot out of it in the low range, he improved a lot.

 

That info isn't on the door jam of a Mack. My rears have a tag on them with the axle ratio...not that that matters at all with the OP's issue. The gear ratio in the rears is behind the transmission, and other than a difference in road speed at a given RPM in a given gear, there is no difference in shifting the transmission. You're using the throttle to match the speed of the input shaft to the speed of the output shaft in the gear you're shifting into. Doesn't matter if you have a 2.64 rear end or a 5.06 gear back there, it doesn't change the technique...only the road speed at which it's taking place.

 

Eaton 13 or 18 should always be shifted 1-2-3-4-5-5H-6-6H-7-7H-8-8H when loaded 80,000 lbs. It helps keep the motor running in the best torque range when accelerating. You are only ever going to need those low range splits if you are pulling B-trains in the mountains in Canada or starting out on a really steep hill.

If you are running empty or bobtail, find whichever gear starts the "cleanest" and go from there. My 379 with a 13-speed doesn't like anything higher than 2 with a trailer or 3 bobtail. I usually always start in L when loaded, because she jumps a bit in 1.

 

@MackRookie this is what I meant when I said that I shift the lower range gears at a much lower RPM than the high range. x1Heavy does a very good job of explaining it. I couldn't even tell you what RPM I shift at anymore, cause I do it all by feel and ear. But I do know that if I have to use all the low range gears the first 4 to 8 shifts happen very quickly (in maybe 150 feet or less) and each gear gets a little more RPM than the previous. But like I said previously I very rarely find that I need to use all those lower gears.

But this same technique can be used whether you are grabbing each consecutive gear, or skipping gears. And as others have explained, this way of shifting does get you moving smoother and quicker than winding up each gear to that higher RPM.

If you watch really good drivers at a stop light when they take off they have very smooth, slower, almost constant, acceleration with little to no hesitation when they shift. Where as a less proficient driver will have faster acceleration but with a second or 2 of hesitation each time he shifts, and the truck may rock side to side more as he winds each gear up to that higher RPM before shifting. This is a classic case of the tortoise and the hare, and often times the slow and steady tortoise will be farther down the road before the hare.

 

I have 18 speed truck. You saying you are splitting gears in low range?? There really is no need for that unless starting out on a hill. Other than that, shift the truck without splitting gears on the low side. Why are you shifting at 1200 rpm? Yeah you gonna miss gears. I think you may need to go back to shifting basics 101. No offense man