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  #11  
Old 08-13-2009, 11:20 AM
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Thanks a bunch folks ! I am really learning alot from this site and its members. What I typically do when downshifting as a newbie I try and atleast get down to 7th gear stop flip the switch to low go to neutral than back to 7th which now will be 2nd and start from there again. What is the difference between a normal 10 speed and a super 10 I dont think I have driven super 10 yet.
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  #12  
Old 08-13-2009, 12:55 PM
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Originally Posted by Flyerfan4life View Post
Thanks a bunch folks ! I am really learning alot from this site and its members. What I typically do when downshifting as a newbie I try and atleast get down to 7th gear stop flip the switch to low go to neutral than back to 7th which now will be 2nd and start from there again. What is the difference between a normal 10 speed and a super 10 I dont think I have driven super 10 yet.
"Normal" 10 has 5 low, flip the switch 5 high. Super 10 - no low/high switch - split shift. 1/2 in one position - start out in 1, hit the switch and let off the fuel (or stab the clutch to release torque) the tranny shifts to 2 (without moving the stick). Move the switch back, double clutch (or float) into 3, move switch break torque and it shifts into 4. You get 10 gears with 1/2 the movement of the stick - as each physical shift has 2 gears.

They're fun to drive, less tiring (less stick movement), easy to get confused and lose track of where the hell yer at gear-wise. My instructor called it "the thinking mans" transmission. You can do a 2 gear downshift with one move of the stick (don't forget to rev). Think of the switch as an odd/even switch and it's easier to figure where you're at. Only 4 guys in my class (of 12) even felt like trying it out - the rest had enough problems shifting ANY transmission. You don't see them on new(er) trucks, I had a lot of fun driving it.

As others mentioned, you don't want to be floating for your road tests (state or company). Just shift the truck with the clutch, be smooth, and don't coast. Turns (at least where I went to school) have to be done in low range. If you're in 7th, drop down to 7-800, clutch into N, clutch out, rev up to 1,600, clutch in and "loop" into 5th (don't forget the low/high switch). You can't ALWAYS get a red light at a turn (much as we like to PRAY for them in school during road testing). You MUST develop the skills to keep the truck in the PROPER GEAR for your road speed/RPM. Lugging/over-revving is a NO-NO.

Rick

Last edited by SickRick; 08-13-2009 at 01:02 PM.
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  #13  
Old 08-13-2009, 01:16 PM
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Originally Posted by SickRick View Post
"Normal" 10 has 5 low, flip the switch 5 high. Super 10 - no low/high switch - split shift. 1/2 in one position - start out in 1, hit the switch and let off the fuel (or stab the clutch to release torque) the tranny shifts to 2 (without moving the stick). Move the switch back, double clutch (or float) into 3, move switch break torque and it shifts into 4. You get 10 gears with 1/2 the movement of the stick - as each physical shift has 2 gears.

They're fun to drive, less tiring (less stick movement), easy to get confused and lose track of where the hell yer at gear-wise. My instructor called it "the thinking mans" transmission. You can do a 2 gear downshift with one move of the stick (don't forget to rev). Think of the switch as an odd/even switch and it's easier to figure where you're at. Only 4 guys in my class (of 12) even felt like trying it out - the rest had enough problems shifting ANY transmission. You don't see them on new(er) trucks, I had a lot of fun driving it.
One of the drawbacks of the "Stupid 10" transmission is that the RPM drop when you are splitting your gear is really long. It's quite easy to flip the switch, let off the throttle, and then hit the throttle prematurely before it has grabbed the gear. When splitting gears on a Super 10, I always popped the shifter out of gear, and immediately popped it back in. Essentially, I was floating the split gear the same way I'd float the standard gear change. It caused the RPM's to drop much quicker.

The biggest thing I noticed about the Super 10 is that I got fantastic fuel mileage out of them. The guy I drove for who had one, had 13 speeds in the rest of the fleet. I easily gained 1 mpg driving the Super 10 truck over the 13 speed truck. At one point, I was averaging 7.7 mpg out of it, pulling a hopper bottom (80,000 on virtually every load). It's a lot harder to gun the truck with that transmission, but it is much less forgiving if you hit the wrong gear.
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  #14  
Old 08-13-2009, 01:20 PM
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Thanks Rick I had heard of a super 10 but had no idea what was different. I have no idea what type of tranny Covenant uses so I am unsure what to expect tranny wise there.
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  #15  
Old 08-13-2009, 02:12 PM
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A few words of caution for shifting without the clutch... you don't want to be unwittingly wrecking things!

There isn't enough good info out there for a driver to learn the principals of clutch use.
Whether you use it or not, it all depends.

"Floating" or clutchless shifting, is too often a juvenile expression of manhood.

As in: "No real trucker would use the clutch" and all that tripe.

For a seasoned veteran of the road, driving a familiar piece fo equipment, it is a fatigue managment technique, for the novice or unfamiliar, it is damaging to the equipment.

If you haven't seen the insides of a truck transmission, make it your business to get someone in a reputable shop to show you how the pieces relate to one another when you change gears. Just walk in and ask some questions!

There are a lot of gear sets sliding on splined shafts that are easily damaged by the misapplication of throttle or shifter movement at the wrong time.

If you feel it rubbing, you are grinding pieces of metal against one another. The word "floating" itself suggests that somehow it's ok to wander the shifter around until it finds somewhere to go. Not so.

Think of it this way: The power of the engine is coupled to the weight of the moving vehicle via the clutch.
You disengage the connection in order to only have the spinning inertia of the gear sets chewing into one another, when you don't get the speeds of the two sets matched correctly by your shift timing/engine rpm managment in the shift. They are intended to withstand that type of wear for many thousands of cycles.

If you leave the power of the engine and the weight of the vehicle connected by leaving the clutch engaged when you shift, then those two very significant forces get to meet against one another on the very tips of the splines or gear teeth, as the case may be, as you try to slide the gear set along that shaft with the shifter.... great if you have the two pieces spinning the same speed, disasterous if you get it wrong.

Any tranny shop will have a twisted shaft in the scrap bin to show you what happens to the splines, and gear sets with teeth chipped off. They'll also have evidence of what those broken teeth do to other parts if they don't fall directly into the pan.

You may have driven or heard of trucks that won't stay in gear? The edges of the gear sets and the splines are so worn down, they are rounded off and the gears won't even keep themselves together with the torque of the engine squeezing them. A truck that won't shift into one or more gear positions? The splines are twisted, the gear sets won't slide along the shaft.

A correction: there is no "time saved" by shifting without the clutch. You have to wait for the engine speed to either slow down or speed up to match the spinning speed of the other gear set you are trying to engage, which has nothing to do with pumping the clutch.
If it is "faster", then your shifting and clutch work has been too slow, and you are putting wear on the clutch with every shift by bumping the engine rpm back up as it has fallen past the engagement speed.

A non synchro heavy duty transmission and its attached engine will only shift at one speed, and that is the speed at which the engine RPM falls enough RPM to match the next gear, or the speed at which you ask it to rise via the throttle. You can't change that. (well, there is the jake switch, but that's another post!)

The smallest wear is of critical importance to an owner operator, as he/she who drives furthest with the least expence wins. Taking out some gears in your own truck? Financial ruin!

I guess a company driver can afford to experiement earlier with his employer's truck.

Ok, so you want to learn the fatigue management technique?

As noted above, get good with the clutch first, every shift for many days, upshift and downshift, goes in without a snick or a grind, the tachometer NEVER bumps when the clutch is let up, you are matching every gear perfectly, every time, the clutch is enagaging and disengaging parts that are rotating at the same speeds, not having to force the egnine to the matching rpm.

On a roadtest to drive my truck, I want to see you shift both ways, so I know you can properly match engine rpm to road speed. But I also like to see a mature and responsible driver use the clutch on those quirky shifts, often the range shift, sometimes a wider gear, the shifts that don't time well, when it would be easier on the gear sets to use the clutch. And I expect that driver to use the clutch for the first few times through the box in order to feel the truck out. Clutchless shifting in a new-to-you truck? That risks communicating the wrong thing to your evaluator. Ignorance, disregard for someone else's property, carelessness, cowboy, all of which probably aren't the impression you are trying to make.

Show an employer you are smart, responsible, and that you know how to care for the equipment.
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  #16  
Old 08-13-2009, 02:56 PM
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I havent seen the internals of a truck tranny yet. I have worked with a freind and helped him change the clutch and complete rear end of his dump truck. My past career I have been a Prevost motorcoach service tech so I have some experience working on diesel engines and repairing air brake fittings and the like.

Last edited by Flyerfan4life; 08-13-2009 at 03:00 PM.
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  #17  
Old 08-13-2009, 03:47 PM
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Every truck and transmission is different and each has their own sweet spot in RPM's when floating. Everyone has their idea and method and you'll find what works for you. I know guys that have been driving for years and still doubleclutch. I would suggest master doubleclutching and just driving skill in general before you attempt to float gears. Most drive tests you will take especially at the big companies will have you doubleclutching so don't forget it. Plus you will hear mechanics tell you two different stories I've had ones tell me doubleclutching saves transmissions and other tell me it tears them up, I guess it depends on who you ask. As for me personally I float because that works best with me. If you get s stiff transmission and need to downshift in a low gear sometimes you will have to use the clutch because sometimes those gears get a little stuck (not literally). Down the road you'll find out what works with you best, good luck.

Last edited by 1TruckDrivinSunUvAGun; 08-13-2009 at 03:50 PM.
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  #18  
Old 08-13-2009, 08:13 PM
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Originally Posted by Hawkjr View Post
... just practice then and then it will become natural too you!!
especially when you get all upset at a shipper and curb a trailer tire, blow it and damage the rim. ;-)
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  #19  
Old 08-13-2009, 08:43 PM
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Once you learn how to match engine speed and road speed you very quickly learn how to float ...Kevin saying he's not that good at floating yet means he's also not learned how to match engine/road speed very well yet either ...WINK
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  #20  
Old 08-13-2009, 11:10 PM
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Originally Posted by LBF View Post
You may have driven or heard of trucks that won't stay in gear? The edges of the gear sets and the splines are so worn down, they are rounded off and the gears won't even keep themselves together with the torque of the engine squeezing them. A truck that won't shift into one or more gear positions? The splines are twisted, the gear sets won't slide along the shaft.
So THAT's what's wrong with my Freightshaker...
Don't be surprised if that happens to you with your truck. With big companies, one often inherits another's problems...
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