Why do I scratch my gears when I upshift.

Hello, this is my first post here. I’ve had my CDL for a year now, and I do local driving for JBHUNT on my dads truck. The reason I am posting this this because every time I upshift it’s just not smooth enough. The higher gears on my Dads 10 speed always seem to feel like if something drops in side the trans. Also I always seem to scratch the gears from 7-10. I bring my rpms up to 1500 to shift from 8th to 9th, by the time I’m hitting 9th something just doesn’t feel right. Yes it goes in but it’s just not smooth. Granted my dad does it nearly perfect, does miss one here and there so I doubt it’s the trans not working properly. It’s just me the one that can figure it out. My biggest concern is jamming the transmission. I live in L.A and have tried double clutching but its just very difficult to do it here with traffic.

Any advice from the top dogs here ? I just really want to be a great driver btw I am 23 yoa

Thanks in advance.

 

the clutch isn't like a car, there are different zones, if you floor the clutch to the floor it's got something called a clutch brake, that stops the clutch completely, that's only supposed to be for starting from a stand still. if you push the clutch too far in while rolling it will stop the clutch completely and it will scratch when you try to put another gear in because it has to spin back up. i spent a good 6 months getting pissed why it was still grinding a little till i realized you only kind of feather the clutch a little to slide a next gear in. i was getting mad flooring the clutch thinking it was worn out and not working right. then i learned how to float gears and quit using the clutch at all. rev it to 1500, slightly pull on the stick before you let off the throttle and it falls out like a turd, slight pull towards next gear on the way down from 1500 to 1200 and it falls right in without a sound. i have an auto now and my shifting is superb.

 

My father taught me how to drive in an old split shift mack. He used the fist system. Chuck is demonstrating it.

 

the more metal you wear off the cogs the smoother the shifts will get

 

I could sit here and type a thousand words. I will keep it as simple as I can. The Transmission has 2 main shafts. An input shaft and an output shaft. That output shaft is directly connected to the rear end and the trucks drives. The input shaft is driven by the engine. Your grinding gears because these shafts RPMs are not in sync. You MUST learn how to shift when these shafts are in sync. In a car these transmissions have a system that helps keep them in sync. Large truck transmission do not!

 

Are you using the clutch?

 

Yes that makes sense. But how do you know when they both synchronized? I have looked at videos that say to raid the rmps to 1500 once you are there you move it out of gear to the next.

 

Normally I don’t use the clutch at all. I float the gears.

 

Yes I understand that and thank you. I have noticed that when my father floats the gears the RPM needle kinda floats between 12-1500 rpms.. when I shift and reach 1500 and pull the shift out of gear my rpms needs drops quickly... so when I try to put it in next gear it feels forced

 

you can either shift quick without any throttle as it falls, or blip the throttle back up where you need it, or i guess if you were a surgeon with your toes you could just let off the throttle a little to let the gear out and keep the fuel on to hold the RPMs where you want them. also if the engine brake is on and you pull the gear out without throttle it will drop RPMs super quick