have a rd test for a job but still have some concerns on shifting

Never downshift more than two gears. I hardly ever go over 1650 for fuel purposes and not being hard on the engine. There is no sense in that.

If you are going to double downshift, then go ahead and slow her down to 700-1000 rpms before downshifting. I like single downshifts from the 1000-1200 range with small bumps. There are variables on engine, transmission, terrain and quick traffic decisions. But don't get in the habit of over revving the engine.
If you have a little puppy dog engine, then you might have to wind her out more. But for the most part you want to keep everything between 1000-1600 with a normal sized engines.
Alot of diesel engines today have max torque around the 1200-1300 range. At max torque you are getting the most out of your engine versus economy. So if you can climb a hill at 1200 rpms, go ahead versus wasting fuel in a lower gear taching 1600 or so.

The bottom line is to know your engine and setup. You can visit the manufacturers website and see the specs and power curve. All that stuff you will learn in time.

Your first post, I don't know what you are driving doing 15 mph in 9th. But with a 9 or 10 speed, if your rpms are around 900, a single shift is around the 1400 area. You could continue close to 700 and double downshift with a bump to around 1600.

Most new drivers with problems are over revving, ease up on the bumps.

Like Pete said, take note of your upshift rpms and downshifting is just the opposite.

 

also u can tap ur brake and get ur road speed down enough to slide into the proper gear ...alot of new drivers dont do this and i am not sure why but it alot better than coasting in a higher gear ...i guess so long as u keep it in gear and dont coast more than a 100 ft u should be ok either way ... i usually drop from 10th to 8th and then i am in the low side after that ...i do it cuz of the tank not so much for style alot of times i know its weird but its how i do it lol ...thats with a eaton 10 spd anyhow and its about what most all companies run now adays anyhow ... u will find ur rhythm and what works for ya ..its all about the rpms and road speed once u got that down you can shift any of these turds on the road effectively

 

I almost always drop from 10th to 9th right away as I am slowing down then drop 2 at a time all the way down then a single drop to 2nd so I shift 10-9-7-5-3-2. I dont think I have ever used 1st in the truck and empty I would not make that last drop into 2nd. Just find it easier that way I am always in a gear I can take back off in.

 

At our school we have 2 trucks we usually drive both with Eaton Fuller 10spds. Look at the shift pattern first and know your vehicle.

R 2 4
|_7_9
| | |
1 3 5
6 8 10

Here is what our instructors tell us. If you are in 10th, to downshift to 9th you should look at the top number which is a 4. Add a 0 to the 4 so you have 40. Meaning you should shift into 9th gear at 40 mph, that is the proper speed for that gear. 8th=30mph, 7th=20mph etc. However that is for our 1996 peterbuilt truck. We also drive an 07 KW T2000. It is a little more higher geared than the Pete, so for our downshift speeds we add a 5 to the top number meaning 9th=45mph, 8th=35mph, 7th=25mph etc. Also with our Pete for downshifting, we have to rev the engine to about 1500rpm for downshifts, our KW we rev to 1350-1450 for downshift. For school we are required to double clutch as well. Every truck is different, so know your vehicle.

 

Shifting was my biggest weekness in school.They had a simulator we could practice on during the weekends and at night.I stayed at the dorm while attending school.Also they had many videos I watched during my off time,all that helped me.

 

Congrats!

My instructors say that company trainers expect some gear scraping at first because every truck behaves differently. I have a hard time with speed / gears, so what I do is just watch the tach. Since I know what gear I'm in, to upshift I know that I need to drop ~400 rpm for each gear when I shift, and to down shift I need to increase ~400 rpm for each gear.