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MANUAL TRANSMISSION | How it Works - YouTube
Channel: Donut Media
[0]
- First gear, second gear, fourth gear,
[3]
sixth, eighth, twelfth gear.
[6]
(engine revving)
[8]
We're talking about manual transmission.
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You probably know the basic idea.
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The transmission changes the gear ratio
[19]
to make sure you're
getting the optimum power
[21]
from your engine to the wheels.
[23]
When two gears are in mesh,
[26]
an almost lossless
transfer of power occurs.
[29]
In this case, a force is
applied to the gear on the left,
[32]
which is in turn moving
the gear on the right.
[35]
For every revolution
the left gear completes,
[38]
the right gear completes one
in the opposite direction
[42]
and with equal force.
[44]
Pretty straightforward.
[45]
What makes gears truly useful though
[47]
is when they aren't the same size.
[50]
Let's shrink that driving
gear down by half.
[54]
Now it has to complete two rotations
[57]
to move the right gear once.
[59]
Well, that sucks.
[61]
But wait a sec, the total amount of energy
[63]
required to move the
second gear one revolution
[66]
hasn't changed.
[67]
But now the driving gear delivers
the same amount of energy
[71]
over twice as many revolutions,
[74]
meaning it requires
half the amount of force
[76]
at any given moment.
[77]
It's like climbing stairs.
[78]
Make the steps smaller
and each step's easier,
[81]
but you gotta take twice as many.
[84]
We've all ridden bikes,
[86]
so you know what it does.
[88]
But how does it work?
[90]
A standard manual transmission
[92]
is made up of an engine
shaft or input shaft,
[95]
and that's the side that
comes from the engine.
[97]
A drive shaft or output shaft,
[100]
that's the side that
goes to the drive wheels,
[102]
and here, underneath both of those,
[104]
is the counter shaft.
[106]
And on these shafts are the gears.
[109]
- How familiar are you
with the gear wars exactly?
[112]
- All of this has to do
[114]
with getting the right amount
of torque to the wheel.
[116]
If you like learning about torque,
[118]
check out our Science Garage
on torque and horsepower.
[120]
If you want to know about
toque and hose powder,
[122]
ask a Canadian.
[123]
(speaking in foreign language)
[127]
But let's get back to the gears.
[128]
- Okay, it was about 754 years ago.
[132]
- If I turn the input shaft,
[134]
the gear on that turns this counter shaft,
[136]
and that turns all of the
gears on the output shaft.
[140]
But all these gears are
moving at different speeds.
[142]
When the gears aren't engaged,
[144]
they spin freely from the output shaft
[146]
because they're not anchored to it.
[148]
Only one gear at a time is
spinning the output shaft,
[152]
and that's because of what is
anchored to the output shaft,
[156]
these hubs.
[157]
Around these hubs are sleeves.
[159]
These sleeves slide over
the teeth on the gear
[162]
and anchor them to the hub
to drive the output shaft.
[166]
But wait, there's more.
[168]
Look at those tiny little teeth.
[169]
Matching up those tiny teeth
at the edge of our gear
[172]
with the sleeves' tiny teeth.
[174]
Well, that's almost impossible.
[175]
So between them are these synchronizers.
[179]
We cut the power to the counter shaft,
[181]
let the wheels drive the
output shaft for a change,
[184]
and when we push the synchronizer ring,
[187]
it gets squeezed against our gear
[189]
and locks it to the hub,
[191]
so it's anchored to the output shaft.
[193]
That's why when you're shifting,
[195]
you get that uh-uh.
[197]
(engine revving)
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Now the wheels in the drive
shaft and the counter shaft
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are all spinning in mesh.
[202]
Voila, we've shifted gears.
[205]
Some manual five-speed transmissions
[207]
may have minor differences here or there.
[210]
This is pretty standard for the most part.
[212]
The big gear here, which is enmeshed
[214]
with the smallest gear in the
counter shaft is first gear.
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First gear is always gonna be
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the largest gear in the transmission,
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producing more torque for the back wheel.
[223]
It's taking a lot of fast turning force
[225]
and making one big slow turning force.
[228]
The slightly smaller gear
next to that's second.
[231]
Then goes third and smallest one's fourth.
[234]
On most four- and
five-speed transmissions,
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fourth gear is what's called direct drive,
[239]
or a one-to-one gear ratio,
[240]
meaning the input and output
[242]
are turning at the same rate of speed.
[245]
Okay, let's pop the shift
fork into first gear
[247]
and engage that big ol'
gear here in the front.
[250]
In first, this particular transmission's
[252]
got a gear ratio of 3.83 to one,
[254]
so I can turn the input, one, two, three
[257]
in exactly 0.8 times,
[259]
and you can see the
output has turned once.
[262]
That's torque, baby.
[263]
Pop it into second,
[264]
and the gear ratio on
this guy's 2.062 to one.
[267]
Third gear is 1.4 to one.
[268]
You know the drill.
[269]
One and .4 turns turns it one time.
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And then as we mentioned
earlier, fourth, one to one.
[275]
They're turning at the same speed.
[276]
That's gear ratios.
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Guys, we did it.
[279]
(children cheering)
[279]
Now a lot of you are probably saying
[281]
what about fifth gear?
[282]
We're getting there.
[284]
Fifth gear is kinda
hidden in the back here,
[286]
and we call it overdrive.
[287]
Remember how first or third
gear were high gear ratios?
[290]
Well, get ready for a low
gear ratio, buddy boy.
[293]
In fifth gear, I only need
to turn this shaft .8 times
[297]
to get a full turn on the output.
[299]
That's overdrive, which gets
mucho better fuel economy.
[302]
At this point, you're getting power
[304]
from the forward momentum of your vehicle
[306]
and don't need as much power
[308]
going to your engine or your wheels.
[309]
Some six- and seven-speed
cars can have double overdrive
[314]
for even better fuel economy
at those high, high speeds.
[318]
Oh, reverse is over here.
[321]
Boop, boop, boop.
[322]
It hits this gear, it
makes your drive shaft
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spin the same direction
as your counter shaft.
[327]
Now here's the rub.
[329]
The drive shaft's attached
to the wheels, remember?
[331]
When we shift gears, the
wheels are gonna want to
[333]
spin the counter shaft
at a different speed
[336]
than the engine's trying to spin it.
[340]
We have to take that power off somewhere,
[342]
or it'll make a grinding sound,
[344]
like when your brother's robot hamster
[346]
won't stop body shaming you
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so you throw it in the blender
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with all the bad forks and spoons
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and press puree to teach it a lesson.
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So where do we let all
that spinning energy go?
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The clutch.
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The clutch looks like this.
[360]
The clutch has a disc
[361]
with a high friction
material on both sides.
[365]
The engine is actually
driving the flywheel.
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And the input shaft to the transmission
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is mounted to the disc.
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When the disc is pressed
firmly against the flywheel,
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it catches and can drive the shaft.
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In the case of this clutch,
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it's squeezed by these springs
[379]
and attached to a pressure disc
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and anchored by this pressure plate,
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which gets bolted to the flywheel.
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Most clutches use three springs,
[388]
but in performance
clutches you can have more.
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And that makes the
connection between the disc
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and the flywheel even
stronger and more effective
[397]
in high torque application.
[399]
Like racing.
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And this is where things
get a little tricky.
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A diaphragm spring is
connected to the pressure disc
[409]
under the pressure plate.
[410]
When you hit the clutch
it pushes the center
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of that diaphragm spring and
that pulls up on the springs,
[417]
which lifts the friction
plate off the flywheel.
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Awesome.
[422]
Now we've disengaged the
power from the shaft,
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but we let off the clutch pedal
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and re-engage the friction disc,
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you're gonna bang, pop right into action.
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We don't want that.
[434]
We want to ease into the movement.
[436]
So attached to the friction plate
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there's these other plates
with coil springs in them.
[442]
These springs are attached to a hub
[444]
and that plate is the one
that anchors the shaft,
[448]
and that goes to the transmission.
[450]
Those springs absorb
the jolt of re-engaging
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the friction plate to take a little stress
[456]
off the other parts of your drive train.
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You want to try to get on
[460]
and off your clutch pretty quickly,
[462]
or you might burn it out.
[463]
(engine revving)
[465]
That happens when the flywheel
and the friction plate
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rub together too much.
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It happens.
[470]
Usually waiting on a hill
to get into a Dodgers game.
[473]
(engine revving)
[475]
So what is a double clutch?
[477]
- Rarely shifting, not double
clutching like you should.
[480]
- Well, it's not really two clutches.
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Double clutch is clutching twice.
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Once when you shift into neutral
[486]
to hit the gas and match the engine revs
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to the gear you want to go into.
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Then you hit the clutch a second time
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to shift into that gear.
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I always use the double
clutch when I'm racing,
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drivin' big rigs, and dunking.
[500]
♪ I believe I can fly, whoo ♪
[504]
- Pretty cool.
[505]
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Follow me @bidsbarto and
follow Donut @donutmedia.
[608]
You like replacing your clutch,
[610]
check out this video on turbos.
[612]
You want to hear about a car
[612]
with maybe the coolest transmission ever?
[614]
Check it out on this Up
to Speed on Conigzig.
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Don't tell my wife I burned out the clutch
[618]
and had to get it
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