jerking truck while shifting

You could possibly have a mechanical problem,

.........

 

Here's a couple references.
Big Duker-Trucker? 27 Years
Diesel Dave-Trucker? 32 Years

 

You should never start in 2nd, especially if you're heavy. Start in low with no throttle. Then after you're in 2nd let the clutch out all the way before you throttle up, and when you do don't stomp it. When you get comfortable with that, try not using the clutch. I had to learn that quickly, as I run team with a very light sleeper. It takes some practice. You'll get it. Hope this helps.

 

If you are "bucking" (that is the correct term BTW) from a start...you are holding the clutch pedal in just enough to be partially engaged as you start rolling. At the moment the truck begins to roll the you should be letting the clutch completely out and applying throttle (use "throttle" so no one gets irritated with "gas" or "fuel"...the pedal is your foot throttle control) equal to the release of the clutch. Don't floor the throttle, ease it down! Jumping on the throttle (right down to the floor) can also cause bucking.

Progressive shifting...and the Cummins engine;

In the first few gears shift at 1100-1200 RPM ... generally 1, 2, and 3.
Next group, 4, 5, and 6 make your shifts at 1200-1400 RPM's.
For the remaining gears, take the tach up to 1400-1600 RPM's.

Remember, for a 10 speed (and a 9) the RPM drop will be about 380-500 RPM's....this is useful for thinking in reverse for down-shifting.

One more thing...when shifting and using the clutch....only depress the clutch about an inch into the "catch zone" (that is the zone where you get when you pass the free play of the pedal). Depressing the pedal more will just throw off your "rhythm"....it kind of goes along with that old saying...."white men can't dance".....or is that jump(?)....anyway...

 

There are a lot of drivers that use this theory....might be the way they learned....actually in a E/F 10 speed, with 80k, 2nd is sufficient for a level (almost level) ground start....but you are absolutely right with NO THROTTLE, just let the idle get it rolling!

 

Back in 1979 when I learned to drive, you would have gotten your hand broken for starting in anything but first gear. Then you would have been walking down the road talking to yourself.

I had a 3406 (first direct injection) Cat, 13-spd, 4.33 rears and 24.5 rubber and always started in first gear. I was taught laziness was the only reason not to. I will admit as time went on I would start in 2nd when bobtailing.

I looked at experience which also reflects when drivers started driving and there is a pattern here. I guess the manufactures and people who spec'd the trucks just put those 2 or 3 low gears in there for ##### and grins.

If you want to make a truck buck give it some throttle while letting out the clutch. All I can say is most of you wouldn't get a driving job if I gave you the road test. If you can't double-clutch and start in first, you wouldn't drive my equipment. Whether you float after the road test I wouldn't care.

 

The references are that is what we have done for 30 years or more and we have the reduced repair bills to prove it works.

The proof that starting in anything but first is bad would be they call it first and the broken equipment that companies deal with every day now days.

Sure you can take off in third and you can drive the wrong way down the Interstate too. Neither one is prudent. The fact that this needs a debate shows the direction that our drivers are going.

For heaven's sake, it's called first because it is the first gear in the shifting sequence.


EDIT: When you go to forums you are getting truck drivers opinions - enough said. Check out manufacturer's specifications and instructions and see if they recommend skipping gears.

 

For the jumping when shifting through the lower gears, you just have to get used to matching the rpms to the speed you are going and the gear you are in. It takes a little practice but when you upshift you will get a feel for how much throttle you need to give when shifting. Also keep in mind when hauling a heavy load up a grade those shift points are going to increase as you will lose speed between shifts and will be below your optimum rpm range for the next gear.

Do I actually sound like I know what I'm talking about?

 

There is absolutley no reason to start in first gear on flat ground loaded or unloaded..... If that's how you wanna do it then fine, but quit telling people their transmission is gonna fall out and they're steering wheel holders if they don't do it the way you were taught 100 years ago.....

 

Who's to say....but if you have change for a nickle you can put your 2 cents in anyway!