Help with 9 speed transmission

NO you don't need to be at the right mph to downshift. That's what everyone is saying. You need to be at the right rpm to downshift. Shifting a truck is more about listening to the engine, and paying attention to the Tach, not the speedo.

 

Exactly. Shifting into 3rd at 15 mph in one truck might be fine but jump into a different truck and you might be wound out at 2200 RPM at that same speed. Speed is and will always be a variable between trucks. RPM range for shifts will always be pretty much the same in any truck you'll ever encounter.

 

There is a "low high". I use it when I'm climbing heavy.

 

DO NOT listen to the engine, read the tachometer, that's there for a reason.

 

Roughly speaking

If his rpm tachometer is 1,000-1,100 rpm, he can downshift 1 hole. If 1,000 or less rpm, he can skip a hole and downshift 2 holes [if in the lower half of gears]. Modern engines can pull across a wide range (road speed and engine rpm) without being a problem. They won't let you over-rev, and going up hills, as long as you downshift at around 1100-1200 rpm, everything will be fine.

When accelerating, shifting up 1 can be done most anywhere from 1200-1500 rpm, depending on load, grade and your mood. Slower road speeds will generally prefer lower rpm shift points.

Memorizing and trying to sequentially shift up and down with speeds is more difficult (mentally and in practice) then it needs to be. Working with rpm (until you develop a natural "feel") is easier and works with any truck and any transmission and drive axle ratio combinations.

 

This is not intended as a put-down of the person who's the subject of this post because there are many hundreds of new drivers on any given day struggling with shifting a manual truck transmission and who were poorly trained, and look for "cheat codes" thinking these will be the solution ... but this is a big part of the reason most carriers are moving to autos.

 

Shifts like a 13 speed, but you can't split high side gears.

 

A ten speed drops 5K with each shift and a thirteen speed drops 3K. 18 speed 3 also.

 

What kind of truck are you driving where it drops 3-5000 rpms with a gear shift?

 

Well from 21 RPMS to 18. What would say that is eignstein.