Double clutching

So the last novellette was about the upshifts and how basically you simply raise the rpm and as they fall back towards idle,you tap the clutch and stick the shift lever in the next higher gear and accelerate to continue the process..

Downshifts, this is the king mother of all newbie problems! Shifting effects all newbies to a certain degree. If the newbie has problems shifting, it will show in EVERYthing else the driver does. When you start driving a truck, your attention is first withing the first couple of feet around the gear shift lever. As your skills and confidence grow, your scope and area of awareness broadens and you are able to see more happening outside the truck. I can tell you from experience with new drivers that the most hair raising moments I've ever had was when someone had a shift problem and instantly reverted back to the "known". The "known" tends to be a car and car behavior! When a shift is blown, the new driver is apt to do anything and usually its not good!

Downshifting is the exact opposite of upshfting (duh). The problem here is we must remember the flight of stairs. imagine that low gear is the TOP of the stairs.. and you are at the bottom of the stairwell... How do you get up the stairs? You have to LIFT your foot up to the next riser.

In a truck transmission, you have to LIFT the rpm to get to the next lower gear. Confusing? yeah a little. So the upshift mantra is "tap- neutral - tap - shift.. We have to add something to the mantra for a downshift. Tap - Neutral - RAISE RPM - tap - shift. This is one area that downshifting can be made easier.

RULE: ALL down shifts are made at the same RPM!

Again: ALL down shifts are made at the same RPM!

Get that? unlike upshifting, downshifting is not made at different rpm (progressively). So set in your mind a rpm to shift at and that STAYS your rpm number! We will use 1000 rpm as a rule. So remember that there are 300 rpm difference (drop) between gears in the transmission. (this may of course vary with equipment)

So you want to slow down and downshift? What do you normally use in a car to slow down? The Brakes? well of course you do! The brakes are the most underused thing in the downshifting by newbies. They KNOW that they need the accelerator, they know they need the clutch, they know they need the gearshift lever. For some reason it completely slips their minds that the brakes are there.

You are cruising along at 60 mph and 1700 rpm or so... You want to downshift, what is the first step?

GET OFF THE ACCELERATOR!

Start FIRMLY and smoothly using the brakes! This does two things, it lowers you road speed AND it drops you rpm! The drop in rpm is what you NEED more than anything. Use the brakes and drag the rpm down. watch the tachometer! (like you'd check a watch.. don't STARE at it) when the rpm drop to 1000.. TAP the clutch and at the same time move the gearshift to neutral..

GET OFF THE CLUTCH!!!

When you get off the clutch SHARPLY "wick" or snap the accelerator to get the rpm UP! now this is the tricky part, you have to snap the rpm up a little over the 300 rpm.. so when you see the tachometer at 1300, TAP the clutch and stick the gearshift lever into the next lower gear and GET OFF THE CLUTCH! as soon as the clutch is released, get back on the brakes and start dragging your road speed down again! This is normally where the clutch crushers start driving around with their foot on the clutch grinding the heck out of the gears!! If you "miss", you have to get off the clutch and get everything moving to be able to sync in back up..

More on this later.. gotta go run cable around the house.. ugh!!

 

I just drove a super 10 today for the first time. Our first time in class out on the road.

I had problems because my left leg/foot refused to "lightly tap" the clutch and wanted to go to the floor all the time.

My question is, would it help to put my seat back a little further so that I can still apply the correct pressure to the accelerator and brake, but can't reach the floor with the clutch?

 

I really doubt it, it may help if you practice "hanging the leg". It will kill your hip, but it will hopefully teach you that the toe is used instead of the whole foot. In most training schools they sometimes have people going through all the gears when its not necessary. Starting in a higher gear sometimes helps.

 

fuzz makes so much sense... i drive a dump truck and i was just threw in the truck my mom drives also but she is in iraq and my father has driven since i was a wee little boy. the only thing that i ever saw was "floating" gears and it took me a while to actually split gears when im driving that seemed to help keep up with the other trucks. im going to try that on the way to the quarry tomarrow. i will practice practice practice but i know how to float em incase... some one said on here before about taking care of the equipment that is so true i do all my normal maitnance i grease the truck every week. i do a pre trip every day ( which i know most ppl dont when they drive but once in a long while) this truck takes a beating going on dirt stop and go hard bumps and you name it. but if i dont take care of the equipment you dont get a paycheck so i take it on my own to learn how to do it right to keep me truckin!

 

Yesterday was actually the first day for me on the road. I had a hard time at first but I think I finally got the hang of it towards the end of the day. I was still ginding a bit but the instructor said even he still grinds from time to time. Now we will see if I can remember everything today.

 

Why can't i give you some reputation points on your post FOZZY ???? You don't have a block at the top so can do that ?? Anyway ,........GREAT , INFORMATIVE , & VERY WELL WRITTEN !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
I would let YOU drive my TRUCK anytime. I have NEVER seen , read or heard that explained so well !!!
Great job , SIR you have earned my highest accolades !

 

hopefuly its not too late to submit my tip.

i got the hang of the timing and such easier by sitting in the truck, engine off,l find any 2 gears it will go into and sit there and practice over and over again. this creates what's called muscel memory.

i did this for a couple weeks during pretrip inspection course (5 hours a day, 8 days, i can only look at the rig so many times before i have to find something else to do) and when shifting class came both the instructor and myself was shocked to hell how well i was able to shift for a newbie.

so give it a try. any 2 gears will work. 2-3 4-5 doesnt matterdo the up and down shfiting technique to give yourself that muscel memory.

 

I started class last wed, and we started shifting on Monday. As of today (the following wed) I can shift well enough to driving around the city learning about tight turns. But just as Fozzy in Oklahoma says I had a very hard time learning to shift because of all my bad habits. I still push the clutch down to far and clutch shift clutch shift....but Im learning the correct way. I did mich better today but I really have to concentrate to get it right. EVERYTHING Fozzy in Oklahoma said in this post is right on. I thank you and everyone else for there help in trying to teach us that so eagerly want to learn.

Thanks again
Ridgerunner412

 

double clutching is a technique that was NEEDED with older style trannys that had straight cut gears

modern trannys (made after 1990) have hellical gears (angle cut) and you can safely float them.

floating gears properly reduces contact wear on your pucks and is a lot less stressful on your driveline (less shock to the joints)...


**** read eatons tech report ****

 

I was taught to float when I trained. I took my test foating, it's just the wya I drive. I can do it much smoother than double clutching.

That said though one thing is being overlooked, mabey most people don't know it. The newer automaticly adjusting clutches HAVE to be clutched or it messes them up. Doesn't much matter, in ten years they will all be auto's anyways