What allows a 5-speed transmission to become a 10-speed transmission is the range selector.
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Down for low, up for high.
The only time you use the range selector is between fourth and fifth.
You"re going from 4th to 5th, pull it up, andf shift to fifth.
If you"re going from fifth to fourth, push it down before you come out of fifth and it"ll shift as you go through neutral.
The splitter gives you 13- or 18-speeds.
So it"s red, blue, or grey.
Red is 13-speed, blue is 15, grey is 18-speed.
The clutch is very different than that you"re going to find on a car or light truck.
Top of it"s the freeplay, the friction point, the dead space and then the clutch brake.
Clutch brake has to be engaged only for starting gears - 1st & reverse.
After that you only push the clutch in 1-inch because if you push it farther than one inch you start to engage the clutch brake.
When you engage the clutch brake you to slow the gears down in the transmission and you"re going to get a rough shift.
Double-clutch to start
One of the other things that you have to do as well is you have to double-clutch: once into neutral another clutch into gear - ba dump, ba dump, ba dump, ba dump.
To Shift a Non-Synchromesh Transmission you have to match the engine speed, the road speed, and the gear.
Those three things have to line up.
And as well, geography is going to start having an impact on your shifting because downhill-uphill is going to affect the road speed.
Therefore you have to adjust the other two variables to compensate for that.
And again the last piece: and this goes for any manual transmission, not just a non-synchromesh - don"t ride the clutch.
As soon as you finish shifting the gear, get your foot off that clutch. Don"t ride the clutch on any vehicle!
The last piece for non-synchromesh transmission: when you"re down shifting, slow down to gear down.
It"s different than normal cars and light trucks.
You got to slow the vehicle down - bring the RPM all the way down to a thousand to downshift.
Hi there smart drivers.
Rick with Smart Drive Test talking to you today about shifting theory for non-synchromesh transmissions.
In your car or light truck a manual transmission is a synchromesh transmission, which essentially speaking or simplistically speaking means that you could go down the road at 100 kilometers an hour, take it out of fifth gear stick it back into first and it"ll go into first...
you don"t want to let the clutch out, but it"ll go back into first.
A non- synchromesh transmission on a big truck you can take that stick out of high gear and try to put it back into first gear...you"ll break the stick off before it goes back into first gear.
It is the driver"s job to synchronize the transmission.
In order to do that you gotta line up:
1) the gear;
2) the road speed;
3) the engine speed.
Those three things have to match or it"s not going to go into gear.
So today, we"re going to talk to you about shifting a non-synchromesh transmission and the theory behind it.13- & 18- Speed Transmissions
Hi there smart drivers welcome back.
Rick with Smart Drive Test talking to you today about shifting theory for a non-synchromesh transmission.
This is for drivers going to driving school and learning how to drive a big truck.
And this particularly is directed towards 13- and 18-speed transmissions.
I will cover some of the other transmissions, but for the most part 13- & 18-speed transmissions.
Now the first part of a non-synchromesh transmission is the shifting pattern: reverse, low sometimes, called bull - 1,2,3,4.
So reverse and low or bull are up here.
First, second, third and fourth - and what confuses students or causes challenges for students is that yes it is a basic 5-speed pattern, but you drive it like a four speed - 1,2,3,4.
The only time you"re going to use low is if you"re starting off with a really heavy load - a set of super B"s at a hundred forty thousand pounds or sixty three thousand five hundred kilograms, or you"re pulling out of a loading dock, or just need to go slow, hooking up to trailers and those types of things where you need a bit of control.
And you use low gear or you"re starting off on a really steep grade and you"re just trying to get the truck going.
But for the most part you"re just going to use first gear.
Now to get to reverse and low, there"s a bit of a wall here.
If you pull the shifter over towards you, you"ll feel a bit of a spring there and that way you"ll know that not only are you in neutral, but you also know where to find low and reverse.
As with all five speed transmission - no matter whether it"s a car, light truck, or a big truck - the shifter rests between the two middle gears.
So for the purposes of a big truck it rests between first and second.
If you"re in your car or light truck it"ll rest between third and fourth, which are the middle gears.
So if you just let go of it in neutral and push it straight forward, it"ll go right up to first.High Range-Low Range
Now you say to yourself, how do I get more gears out of a 5-speed transmission? So the way that you get more gears on a 5-speed transmission in a big truck is on the front of the shifter is the range selector - down is low and up is high.
The only time you use the range selector is between fourth and fifth.
So for fourth to fifth you push the range selector up - you pre-select the range selector - flip it up with your middle finger, push the stick into neutral, let go of the stick and push straight forward.
It will go back into fifth on the high range.
So think of it like a downstairs and upstairs.
The range selector is the staircase that takes you up to the top five gears.
On the top, you"ve got another five gears 5,6,7,8.
So basically if you"re driving it like a four-speed, as you will in a 13- and 18- speed, you now have eight gears.
If you include low you now have a nine-speed and in the ten speed transmissions, what happens is that instead of going back to the fifth gear, which is up here, you go out of eight and over and down to low which will give you ten gears.
So those are the variations for eight nine and ten speed transmissions.
However in this day and age, most of the transmissions that you"re going to drive are going to be 13- or 18-speeds because the technology has advanced and moved forward and they"re much more robust so they"ve infiltrated the industry and really those are the most common transmissions that you"re going to find on big trucks now.
So you now ask yourself we"ve got to eight, nine, or ten gears - ten gears for the purposes of simplicity.
How do we get 13, 15 or 18 gears? And what happens is on the side...on the side of he shift lever is the splitter.
The splitter allows you to split the gears in the top range.
If it"s red, it"s a 13-speed; if it"s blue, it"s a 15-speed; and if it"s grey, it"s an 18-speed.
Now let"s just talk about 13- and 18- for just a moment because 15-speeds are different than 13 and 18.
So what happens in a 13- speed is 1,2,3,4, flip the range selector up and go back to five - five, six, seven, eight, and then what happens in the top range is that you can split each one of the gears.Splitter
So low-high, low-high, low- high, low-high.
So you shift from 4th to 5th: 5-lo, push the splitter forward, take your foot off the throttle - break the tension in the drive train--wait a moment, let the RPMs drop a couple hundred rpm, back on the throttle - it shifts to high.
Pre-select back the low, shift to six like a normal shift, six-low six high - pre-select back to low - seven lo seven high, pre-select back to low 8-lo 8-hi.
So what happens is you get five on the bottom...low 1,2,3,4 - range selector up to high, back to 5-lo 5-hi, six-lo six-hi, 7-lo 7-hi, 8-lo 8-hi.
So you get five in the bottom, eight on the top.
5 + 8 gives you a 13-speed.
And that"s how you get 13-speed.
Now how you get an 18-speed is that you can split all the gears on the bottom and all the gears on the top so you get 10 gears on the bottom and eight gears on the top, which gives you an 18-speed.
Now an 18-speed is a glorified 13-speed.
You"re never going to split the gears on the bottom, unless you"re running around a gravel pit, or you"re one of those Ice Road Truckers.
You"re just not going to do it, it"s too much work!
So essentially, what you"re going to do is a 13- and 18-speed transmission - both of these transmissions are going to be driven like a 12-speed.
1,2,3,4 - four gears in the bottom, eight gears on the top - so it"s essentially a 12-speed.
And you"ve got to get your head around that.
And that will be your challenge at the beginning of learning how to shift a non-synchromesh transmission.15-Speed Transmission
Now I"ll just touch on what a 15-speed is for a moment.
If you get in a truck and it"s got a blue button in it, it"s a 15-speed.
Now this is not a splitter in a 15-speed transmission.
This is what is called deep reduction.
And the best way to explain deep reduction on a 15-speed is that essentially you"ve got three tiers of five gears.
Five gears way down in the basement, five gears on the main level, and five gears upstairs.
Most of the time you"re going to drive a 15-speed like a ten-speed.
1,2,3,4,5, flip up the range selector, back over to low - and for those of us who drive 13s and 18s and then get into 15- that"s very weird for us to go back to low - but back to low 1,2,3,4,5 shift it like a ten-speed.
Now if you get into a gravel pit or something like that you need deep reduction, the best way to understand deep reduction in a 15-speed is like four-wheel drive low and four-wheel-drive hi.
That"s the difference.
And it"s not sequential, so if you"re in deep reduction in 15-speed you can"t go one, two, three, four, five and then split up to the next gear and go the other five.
It"s more like up to five in the low low and then up to three on the next level.
So it"s a little bit strange, but if you ever get into a 15-speed, just kind of play around with it and you"ll get use to it.
But know that if the splitter is blue it"s a 15-speed; if it"s red, it"s 13; and if it"s grey, it"s 18.
And in this day and age of non-synchronous transmissions, most of them are going to be 18-speeds.Crash Box - What we call a transmission in a big truck
In a non-synchromesh transmission or sometimes referred to as a "crash box", the driver has to synchronize the transmission in order to make it shift.
And the way that you make it shift is that you have to match the engine speed, the road speed, and the gear.
Those three things have to line up or it will not shift.
And these variables will change depending on the terrain, so you need to now pay attention to geography - uphill, downhill.
If the truck is slowing down going uphill you don"t need to give it as much throttle to shift.
If you"re going downhill, the road speed is going to pick up, therefore you need to shift the gears faster or you need to skip the gears in order to keep up with the accelerating road speed.Transmission Speed
The other thing about these three variables - engine speed, road speed, and the gear--is that the engine speed is a misnomer.
It"s actually the gears" speed and the transmission that we"re measuring the speed of, but we don"t have any way to measure the gears in the transmission and how fast they"re spinning, so we use the engine"s tachometer.
The engine"s tachometer tells you how fast the engine is turning over.
Now in order to spin the gears in the transmission, we have to reconnect the transmission to the motor and you do that with the clutch.
And I"ll talk about double-clutching here in a moment.
Because in order to shift a non- synchromesh transmission and to make these three things line up: 1) engine speed; 2) road speed; 3) and the gear.
You have to double clutch, you have to reconnect the transmission to the engine in order to determine how fast the gears in the transmission are spinning.5th Gear is "The Happy Gear"
One of the gears that we like the best is fifth gear.
If you lose a gear and you"re trying to recover and find a gear - eighty-five percent of the time the transmission--a 13- or 18-speed transmission--will go into fifth gear.
So fifth gear - up here with the range selector up, back to the first slot - fifth gear is your go-to gear.
85% percent of the time the truck will go back into fifth gear and you can carry on.
Sometimes it may not be pretty, but you can get it back into fifth gear and go.
As well, fifth is you"re up to the lights slow gear.
When you"re kind of idling up to the intersection, timing traffic, trying to keep the truck moving, fifth is gear is the one you want--up to the lights slow gear.
Fifth is also the highest gear that the truck will idle in.
You can take your foot right off the accelerator and the truck will just kind of chug, chug, chug, chug, chug.
Fifth gear is the highest gear that that truck will do that in - fifth gear.
Finally, fifth gear is the first gear that the truck actually begins to accelerate - actually begins to pick up speed.
So we need to get through those first low gears as quickly as possible to get up to fifth gear.
And the faster you get through these low gears, the better fuel economy you"re going to get on the truck.
So move through those first four gears fairly quickly up into fifth because we love fifth.
Fifth is that go-to-gear.
It"s that happy gear! Its kind of like when you go home at the end of the day and your partner looks at you and gives you a wink and a nod - that"s fifth.
So love fifth - fifth is the happy gear.Low Range; Low Revs—High Range; High Revs
One of the other things that we talked about in trucking and in terms of shifting a non-synchromesh transmission is progressive shifting.
And basically progressive shifting was designed and implemented out on the flat on the east coast, where there aren"t big mountains and whatnot.
It works well on the flat - doesn"t work so well in the mountains.
In the mountains it"s more of a variation on a theme.
And my variation on shifting in the mountains is low range, low revs; high range, high revs, because if you start climbing hills, especially if you"ve got a big load on, you"re going to have to bring your rpms up and compensate for drops in road speed because of gravity.
So progressive shifting is essentially every gear you bring your rpms up 50 rpm.
So if you started at 1100, shifting to second and you bring it up to 1150 to shift to third and bring it up to 1,200 to shift to forth and so on and so on and so forth.
1 to 2 is 900, 2 to 3 is 1000.
3 to 4 is 1100- 900, 1000, 1100.
Now if you go to a driving school, different instructors are going to have different interpretations of that.
But that"s essentially what I say, "nine, ten, eleven and once you get some practice, you should be able to move through those first three gears fairly quickly.
Pre-select the range selector and back up to five.
Once you get up to fifth gear, then you can start bringing the RPMs up.
Because you"re into high range - high range; high revs.
You need to bring the RPMs up 13-1400 RPM, once you get to 5th, 6th, 7th, 8th.
You don"t need more than 1500 rpm in a big truck - a big electronic diesel engine.
Unless you"re climbing hills, you just don"t need more than 1,500.
The peak power band on large electronic diesel engines - and I know that different guys will tell you different things--oh, it"s a Cummins, it"s a Detroit, it"s a Mercedes, whatever!
It doesn"t matter - big electronic diesel engines - the power band is somewhere between 1200 and 1500 rpm.
I drove a Peterbilt last fall within EPIQ engine - its Paccar"s own engine.
The sweet spot on that engine was between 1200 and 1400 RPM and there was actually on the tachometer was a spot called the "sweet spot."
And it was right at 1400 RPM, so keep that engine between 1200 & 1400 rpm to get maximum fuel economy.The Clutch
The other piece on shifting a non synchromesh transmission in a big truck is the clutch.
Although the shifter and the clutch, and everything else looks kind of the same as it does in a car or light truck, it isn"t anything like it is in a car or light truck.
And many a student gets in the truck and go: "I got this!"
And then they realize after the first lesson that it"s going to be a lot more challenging than they ever imagined.
So the clutch in a big truck:
• the top part is called the free play....
• the next part is called the friction point...
• next part is called the dead space...
• and the last part - right up against the firewall here, that"s the firewall - is called the clutch brake.
So the four points of the clutch:
1) free play;
2) friction point;
3) dead space;
4) and the clutch brake– right at the bottom.
Top of the clutch is the freeplay.
Nothing happens there – next point is the friction point: the friction point is where the engine begins to reconnect with the transmission and the vehicle moves forward.
Behind the friction pointis the dead space.
The dead space is where you hold the clutch when you"re waiting at a traffic light or waiting to go.
So it"s in behind the friction point is the dead space.Clutch Brake - it"s at the bottom
At the bottom - right up against the firewall - is the clutch brake and the reason that we have a clutch brake in a non-synchromesh transmission, is you have to engage the clutch brake to get the vehicle into a starting gear; whether that"s first, second, third, or reverse.
Whatever you"re starting gear is, you"ve got to push the clutch all the way to the floor, pause, hold, and put it into your starting gear.
If it won"t go into the starting gear, hold the selector against the gear, and ever so gently let the clutch out until it drops into gear.
What happens is that the gears don"t quite line up, and it won"t go into gear, so you"ve got to just rotate the gears a little bit.
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So hold the stick against the gear, and then ever so gently let the clutch out and then just push it back in.