I want to show you how pretty
much every automatic transmission that has planetary
gear sets works. And it's actually pretty simple. And I
think once you see this demonstration, all the parts
that you've taken out of these transmissions that we've
disassembled these Allison's, and any other automatic
transmission that you disassemble will suddenly make
sense as to why they're there and what they do. But this is
something that as a young technician, I couldn't grasp at
first, but finally figured it out. So we've got in a
planetary gear set style transmission, we have a
planetary gear set. And a planetary gear set consists of
anybody know what this is called? The sun here, it's in
the middle. So think of our solar system. We have planet
years, that of course, orbit around the sun gear, the sun
gear rotates inside of them, those planets gears, these are
the planet gears are held in place by this house, this part
here called a carrier. So this is the planet carrier carries
the planets. And that orbits around inside of anybody know
what that's called. Sometimes it's called an internal gear,
sometimes it's called an annulus gear. Most of the time that I've
seen, it's called a ring gear, so think of like a ring on your
finger ring gear, so we've got a rain gear, a planet carrier, and
a sun gear. Now mathematically, if you change the size of the
sun gear versus the planet gears and leave the ring gear size
alone, you can change the gear ratios that this planetary gear
set can create and all planetary gear sets can create some useful
gear ratios and some absolutely crazy gear ratios that are not
useful. They can all create to underdrive gear ratios and what
is under drive me. Okay, so yeah, like low gear and your
transmission first, second, third, whatever it may be, the
output shaft of the transmission is going to be turning slower
than the input shaft at the transmission. So that's
underdrive. So there's two under drive gear ratio is one is
a usable one is unusable. It's just an it's a gear ratio.
That wouldn't work. Although it is underdrive. There's also two
overdrive gear ratios. So overdrive means output shaft
turns faster than the input shaft so one of those is usable,
and the other one is insanely unusable. So on most overdrive
transmissions today, the final overdrive gear ratio is around
point seven turns of the crank shaft to one turn of the output
shaft. I've seen as low as point five turns half a turn of
the engine crankshaft gives you one turn of the output shaft,
but not very often. Well, one of the unusable gear ratios in
overdrive on most planetary gear sets is like point two. So it
just it's mega overdrive, it's not going to work. There's also
to reverse gear ratios. So one of them is usable one of them is
not. And then there is what's called direct drive. And direct
drive means what? The one to one input, the what? One, turn n
equals one turnout. So that's directed graph. So these, these
gears right here can make up a single planetary
gear set and typically in a in anybody's automatic
transmission, this is you can get two forward gears out of
this, one of the underdrive gear ratios and a direct drive. You
can also get a reverse gear ratio out of this and possibly
in an overdrive depending on what the gear ratio is, but
typically for each two years in a transmission, you need one set
of planetary years. So the old Powerglide transmission had one
planetary gear set in, it was a two speed. But when we have a
four speed transmission, it has two planetary gearsets in it,
and five, six and so on. This Allison transmission that we're
working on in class is a five or a six speed, and it has three
planetary gear sets. So pretty much two gears per planetary
gear set. Now there are exceptions, there are some
sneaky configurations where they can hook multiple pieces, or
multiple gear sets together with a common sun gear or a common
carrier. And we'll talk about some of those later. But let's
stick with the basic ones. First, just a sun gear a planet
gear, or planet carrier with planet gears and a ring gear.
Now, these gears happen to be out of General Motors for L 60.
E transmission. So that Chevrolet total we had in here,
the 2007 Tahoe with four-speed that we had for the manual drive
during class that had the these were called the input planetary
gear set. And it had an output planetary gear set also, but two
planetary gear sets. So let's let's do a comparison with the
Allison. So here's four l 60. E, sun gear, here's Allison. Some
gear. A slight change in size. But it's all relative. Here is
the four l 60. E carrier, but I can't even lift it. That's the
carrier from the Allison, and it has three of them that are very
similar sized. And then of course, here's a ring gear.
Also, so obviously a much bigger, more heavy duty
transmission. Yes. No different concept. It's called
the ring gear. Well, you can still get it, it's similar
in some ways, because you can have a similar gear reduction,
or, or overdrive, but planetary gear sets are compact. And one
of the neat things about planetary gear sets that allows
them to be used in automatic transmissions is how you
transfer power through a planetary gear set. So unlike a
manual transmission, where we had synchronizers and actually
had to move, shifts, leaves and everything in and out to shift
different gears a planetary gear set. Right now, this one on the
portal 60 II if this sun gear was hooked to the input shaft,
and this was hooked to the output shaft or driveshaft, and
this is hooked to the ring gear by the way. Notice right now, if
I turn the sun gear then there's no power flowing through the
output shaft does not turn. So instead, we have to come and
come in. And we have to hold one of these three pieces from
rotating and rotate one of the others so on a planetary gear
set to get reversed to get forward to get any of those
usable or unusable gear ratios. Out of all three pieces, you
always have to hold one and drive the other one or drive,
there's three pieces. So you're going to hook power to one,
you're going to stop one from rotating, and then the one
that's leftover will be your output to the to the trance to
your wills. And so in this case, if I held the carrier from
rotating and turn the sun here it looks like I've got reverse
right there. So there's one reverse gear ratio. But if I
hold the sun gear from rotating, and let's say we hook to the
carrier to the output shaft rather than the sun, or than the
ring here, so I'm holding the ring gear, I'm going to turn the
sun gear if we could connect the planet carrier to the wheels.
Notice as I turn the sun gear, the planet carrier turns with
the sun gear in the same direction, but it's actually
turning a little bit slower. So this is an under drive gear
ratio. So what I'm trying to show you is it's much easier to
show it on the Allison just because of how it's designed is
that once again, to get power through any planetary gear set.
You have to stop one of the three pieces. We can Stop the
watch, this will go into overdrive. I'll hold the sun
here from rotating. And then I'll turn the planet carrier.
And now the ring gear turns faster than the planet carrier
that I'm rotating. And so there's an overdrive, but we
have to hold one of the three pieces, turn one of the other
three to get underdrive, overdrive or reverse. Now the
direct drive is unique because indirect drive, you don't, it's
the only one where you do not hold anything and prevent it
from rotating. Instead, you connect power to any two of the
three pieces at the same time. So if I connect power to the sun
gear and the planet carrier, and rotate them together, it forces
the ring gear to turn with it. If I hook power to the sun, and
the ring, it forces the carrier to turn with it. If I hook power
to the carrier in the ring, it forces the sun to turn with it.
So there's three different ways to get direct drove here, easily
connect the power to hydraulic solenoids to control the
pressure to push, we're coming to that, but just when I say
connect power, I mean, somehow we're hooking the engine to one
of these three pieces. So engine power coming in, the output is
going to move the vehicle through transaxle or rear axle,
whatever, whatever it may be. So what I want to show you now that
we've seen basic pieces of a planetary gear set is the how
the Allison transmission with its three planetary gear sets
can give us five or six speeds plus reverse. So let me let me
get these two pieces. Actually, let me pass these
around you can take a look at all right, so let's uh let's
start let me back up over here on the bench and this is what I
want you guys to do with your Allison's today. We've got this
red holding fixture that that sticks out. And when you got
your transmission disassemble, you're going to have what do
you think the name of this part is with these little gears on it
when a carrier so there are three planetary gear sets in the
in the Allison transmission, this planet carrier is actually
connected to the output shaft. So this, this flange right here,
notice turns with the output shaft and the planet carrier.
This piece right here with all these notches in it is the
parking here. And I just wanted to show you the Allison has a
massive parking gear. I don't know how wide that is internet
engineer quarter So, but this is what's called the parking, Paul.
And notice it's got this little hook on it. And if you ever
accidentally on the hoist had the vehicle in gear, tires
rotating, and then you accidentally forgot to step on
the brake and you put it in park and you hear this grinding
noise. That grindy noise is this park Paul trying to grab until
it finally does. Now of course it was never meant to do that.
And eventually it would cause damage to the parking Paul or
the parking here. Both of which are replaceable, but very
expensive. Of course, on the Allison, this is a gigantic.
This is easily two or three times the size of a regular
parking Paul saying that for L 60. E that we had. It's a
monster room. It's made to hold a lot of weight. The last cross country series we
have one that we requested that was engaged to the whole bus
they kept on rolling in the train to a car. Yeah, it's not mad. It's not
meant to stop the vehicle. It's meant to prevent it from rolling
once you are stopped. Okay, so this is one of three planet
carriers. Here's the other two right here. So we've got the P2
gear set, the p3 gear set and the Pone gear set. I don't
have it labeled over here. But for Allison, as far as Allison's
terms, pone just means planetary gear set number one p
twos. You're set to be threes gears at three. And they're in
that order from front to rear of the transmission. So the Pone
obviously is closer to the front of the transmission, and then P2
and then P3. So those are the three planetary gear
says. So now I want to start assembling these pieces for
assembling the planetary gear sets. So you can see how this
thing works. So every planet carrier has to have to be a sun
gear to go with it. So here's a monstrous beefy sun gear. By the
way, in between every one of these rotating pieces is a
berry. And those bearings, there's a bearing down in here
that sits in this groove, when you get these gears lined up,
which sometimes can be a little bit of a challenge there,
they're finally lined up, do not do this. You might as well take
a hammer and smack the bearing with it because that thing
probably weighs a pound that some euro by itself, so you can
damage the bearing itself. Well, there's a sun gear that went
inside the planet carrier. And over here, the ring gear for
that gear set also happens to be connected to the planet carrier
for the P2 gear set. So they connected a ring gear and a
planet carrier. Together. This is called a compound gear set. So
a simple gear set is just that for L 61. I showed you just with
the three individual pieces, but a compound planetary gear set is
one where they start hooking them together. Yes, so in before
I can put that ring gear on, then there's another sun gear
that needs to sit on top of this. And guys, when you put
this Allison together, there's a spacer that goes in between
these two sun gears. Like that. There's a bearing of course that
sits on top, notice this bearing has been destroyed. Broken, you
see the bearing. That's because when whoever lined this up,
before we dialed tested, it did not get it centered. In the sun
here they had it off to the side. It was the previous
troublesome student and when they put it together and just
kind of squished everything and, and broken. So anyway, there's
two sun gears. And then in this case, there's what's called our
intermediate shaft. So on this transmission, we've got the
input shaft from the torque converter and the engine. We've
got the output shaft that goes to our driveline or transport
case. Table and then there's a shaft in the middle. Are these that going to connect? Oh, that
they're upside down? is going to connect those together. Kind of
a trick? Yes. All right, first one. Working here what was on the
last year set on the back of the transmission? Did they put
anyone on the transmission or does it have to be noticed it's on the output shaft
because the parking gear physically stops the drive shaft
from rotating which stops the ring and pinion from rotating
which stops the differential case. Living in pin axle shaft
that's the only thing holding you from rotate from rolling,
which if you think about it, if you're parking on it a pretty
steep hill and all you do is throw it in park. It can let go
and did let go. Yeah, exactly. Okay, so I've got an
intermediate shaft finally installed. There's great
orientation, or to some gears, we've got one planet carrier. So
now we've got the second planet carrier with the ring gear. It's
going to go with it. Once again, this is a heavy part. We've got
bearings in between. So we're going to have to line this up and
carefully set it down. So now inside here, I've got a sun gear
a planet carrier and a ring gear for the p3 gear set. But I've
also got a sun gear and a planet carrier and planet gears for the
P2 gear set. That's next. So notice the P2 gear set, ring
gear is also connected to the P1 gear set, planet carrier.
And there's a barrier right here that needs to be centered. So
we're going to set that in place and set it down. So the gears that drive the
vehicle are the set of their interview. We're coming to that.
Hang on to that question. Alright, so now we need another
sun gear, which is right here. And another ring gear right
here. So let's put the ring gear on first. You guys are going to
have to assemble your transmissions in this this same
way. And then the sun gear is actually part of that big
rotating clutch housing. Yes. He said the relationship of
changing the gear ratio is changing the size of the Sun
near to the to the planet. Yes. So the ring gear size isn't
changing on any of those. That's right. It's the same. So is
it like a different pick the size of the Sun here, you
divided by how many people on the planet? ratio? The math is
right there if you want to. Okay, so why don't we just ask
like, how come you said before 16? Is uncompounded? How come? No, I said that one gear set. Oh,
that was a simple gear set. But in, in reality, it does connect
to the output gear set and becomes a compound. But a simple
gear set is just like the Powerglide hat. It's just a
single planetary gear set. The the sun gear for the Pone gear
set is connected to the rotating clutch module. And can I get you
to just grab that hole, rotate that big housing with the input
shaft right there. Yeah, set that right over here. Just right there. Right, this is the rotating
clutch module. And this is just the bottom of it. So all of you
are taking this out, you either have it out or we'll take it
out, we're going to today will take that apart even further.
Because inside of that area couple of clutch packs that we
need to talk about. But what I wanted to show you on this sun
gear is that it is splined directly to this piece of metal
that is splined on these notches directly to this housing that is
splined directly to our input shaft, which means if our input
shaft turns at all, and of course I can't get this to line
up. There we go. If the input shaft turns at all, so does this
sun gear, it requires no computer requires no clutches,
it's just a direct connection to the engine. Once the torque
converter transfers its power. We're going to talk about how
torque converters work Friday morning. I've got a
demonstration on that to show you but anyway, planetary or sun
gear is our third sun gear. So now I'm going to set that right in
here just like that. So now we've got three complete
planetary gear sets here. We've got the Pone gear set, I just
put the sun gear in. We've got the ring gear I just put on and
then the planet carrier, its planet carriers connected to the
sun gear, I'm sorry, the ring gear of the next planet gear
set, and so on. But we've got three complete gear sets. There.
They're all connected to each other. And so now we're ready to
add a few additional parts. This shaft the intermediate shaft
that I showed you earlier, has some splines right here. Well,
this shaft if we remember went down and hooked up to some gears
down below. Well, we happen to have another housing right here
that has teeth. It's called the Cone clutch housing and it
hooks to that shaft which means if this housing right here turns
at all those to some gears turn because it's connected directly
to it. There's another housing with splines, these set of
splines right here connected to the planet carrier, and the ring
gear for the P2 and the P3 gear set, and there's
another clutch pack right here, clutch pack housing for a C2
clutch that connects to that. So what I'm trying to show you
remember is a planetary gearset has to get power to flow through
it, we have to stop something from rotating. And we also have
to force something else to rotate out of those three
pieces. So we have a way to touch every sun gear and every
planet carrier with all of these pieces, so let me put this
together all the way now. Okay. Now we have on the input side of all
of these planetary gear sets, we can connect engine power to the
Cone clutch housing, the C2 clutch housing, or this rotating
clutch housing that had that sun gear to it. So these three
pieces are going to individually or together be connected to the
engine somehow. And I'll show you how that happens here.
Remember, these ring gears right here are going to, they're going
to be held and stopped from rotating by the clutch packs
that connect to them. So in this transmission, we actually have
five clutch packs. And let me let me show you one clutch pack
right here. This is called the C1 clutch pack. And it's
connected right to the input shaft that hooks to the engine.
The Cone clutch pack, like every clutch pack consists of
metal plates connected to fiber plates. And as you guys have
disassembled or will disassemble your transmission, you've come
across all five clutch pack sets. I've already showed you
the Cone clutch on the input housing. Here's the C2 clutch
or on the input shaft. Here's the C2 clutch inside of this
rotating clutch housing. So the C1 and the C2 are inside
of that big housing that we just brought up. And that those hook
to the engine. And then here's the C3 clutch pack. And
notice it's alternating still fiber, steel fiber. And what
well, I'll describe how these work here in just a minute. So
that's the C3 clutch. Here's the C4 clutch. And
here's the C5 clutch in the back, very back of the
transmission. Okay, so these three clutches right here,
the C3, the C4 and the C5. They have teeth in them
that spline to the case of the transmission. So did you see all
those slots in the transmission inside the housing. So these
steel plates fit down inside the housing, they will never rotate.
They're locked in place with these with these notches,
and then the fiber plates right here. push this out of the way,
here's this, here's a C3 clutch plate, clutch fiber
plate. Here's where the C3 clutch connects right here to
the Pone gear set. So if I if I just pull those three pieces
off, notice that the fiber plate splines right to that p3 gear
set. So I'm sorry that the Pone gear set with the C3 clutch
so this can spin like crazy with the wants. But when we want to
stop that ring gear from rotating, all we have to do is
somehow act like a disc brake and so think of This as being a
disk brake with multiple rotors. So here's a rotor, here's a
rotor is a rotor, we've got all these disks. So we will have a
steel plate, a desk, a steel still play, and other days and
other still played. We'll just keep stacking and stacking and
stacking, the steel plates will never turn because they're
hooked to the case, the fiber plates turn because they're
hooked to the ring gear. So anytime we want to stop that
ring gear, all we got to do is squish these together. Does that
make sense? The transmission case itself is what's stopping?
Yes, yes, the case itself through these steel plates
cannot rotate. And so if we can squish all these steel plates
together, because they can move up and down this way, then it
stops all these fiber plates from rotating which holds this
ring gear from spinning. So what I'm telling you is any time
let's go back to the anytime a C3 clutch is applied, it's
going to stop this ring gear from rotating. So now look at
your little clutch application chart here. Notice
anytime the C3 clutches applied, it's going to stop the
Pone ring gear from rotating and what gears is that applied
in reverse third and fifth Do you see that it's kind of a
light green color right here on these charts. So in reverse,
we've got the C5 clutch applied and the C3 clutch
applied. In third we've got the C3 and the Cone in fifth.
We've got the C3 and the C2 So in in certain gears
we're going to stop this the C3 clutch from rotating. Now
the same thing is true for the C4 clutch, the next clutch
that's down in the in the transmission except the C4
clutch instead of stopping the upper ring gear stops this
centering gear and the C5 clutch stops the bottom ring
gear from rotating. So out of these five clutches, these three
act like brakes. These are going to stop the ring gears of the
planetary gear sets. Does that makes sense? These two, the Cone clutch and the C2 clots that are in that housing that
rotates with the engine when the torque converter transfers
power. They are the ones that are going to connect to pieces
of the planetary gear set and rotate them and just happens to
be that they're all sun gears that they rotate. So we've got
this bottom sun here that hooks to the housing that has power
transferred directly from the engine without any clutches. So
that that's the sun here that's going to rotate. We've got to
C1 plots that splines clear down to the sun gear for our
nodes, the planet carrier, not the sun gear planet carrier for
the second planetary gear set. And then we've got to C1
club with splines to both sun gears at the bottom. Now, every
I told you if you can understand what I'm about to show you here
next. The same thing applies to any trance any automatic
transmission with planetary gearsets. The difference, the
only difference is whether we're taking a Ford or Chrysler or GM.
Toyota does not matter. I've had them all apart, or versions of
different or different models of party in my classes over the
years, they all have these. It's just that where they're located
in the transmission might be different. Their size might be
different, which parts are held versus which parts are rotated
might be different. But so what it's all about whether we stop
or rotate a piece of that planetary gear set to get our
different years whether it's a two speed or a 10 speed.
Automatic it's still the same principle. Yeah. How many years?
Could they get out of that one? usable? Here's only six usable.
Yeah. But a lot more gears. It's just that they would be your
ratios that are unusable. It'd be way too overdrive away to
underground. Yeah, it's their ridiculous numbers. So in order
for them to keep adding, they either add another gear set
or they do a tricky column. One thing that will, we'll come to
later in the class, there's one called a Simpson gear set.
There's one called a Peltier a gear set that, but there's still
planetary gear says they just connect different pieces
together. It is. So let's think about all of the parts that
you've taken out of this transmissions. so far.
Everything you've taken out of the guts of this transmission
is related to clutches. And those clutches, the job of those
clutches is either to hold or to turn pieces of a planetary gear
set. So I don't care how many clutch packs you have or where
they're located. That's their job. So remember, I told you
inside of transmission, I like to think of there being three
main groups of parts. This is the mechanical group right here,
these are the gears, this is like your manual transmission.
But then we've got all the clutch packs that do the
holding, or the turning of all of those pieces. And then we end
we'll come to this later in the week, we've got the hydraulic
and electrical portions of the transmission to talk about also
because we the valve body is what controls when these clutch
packs are applied or released. So we've got the gears, we've
got the clutches that apply and release them. These the
hydraulics do the applying or the releasing of these clutches,
the electronics are now controlled by a computer that
decides when do you apply and release these clutches? And
that's it. That is it. So I don't care if this thing has 367
pieces. Every one of those is totally dedicated to holding or
turning one of these planetary gearset pieces and the timing of
when it's done. And how it how it feels when it actually
shifts, do we you want the shift to praying every time or you
want a nice smooth upshift. And it turns out its variable
depending on throttle angle and vehicle speed. And so there's a
lot of a lot of inputs. Whoa, whoa, whoa, it changes when and
how hard it shifts. Sometimes it even keeps you out of an upper
gear depending on which transmission it is. But all of
those pieces that seemed so overwhelming to me as a young
technician looking at another auto trans guy, they were just
clutches, and then in that in the with the clutches, we've got
pistons, these are pistons, you guys have pulled out the C3
and the C4 clutch piston. These pistons are the ones that
come in hydraulically and push on these clutch packs to apply
them or to release them and so we'll explore the hydraulics. So
we've got a clutch piston for the C3 and the C4 the C5
clutch piston is a little bit bigger, and it's spring
loaded. Right over there. The C1 and C2 clutch pistons are
inside of that rotating clutch housing. And so we'll
explore those. But let's take a look at what I want you
to do today with your planetary gear sets. I'm going to take you
through all six forward gears and reverse and show you that
it's actually pretty easy to do all of this. So looking at the
clutch application chart on the back of your three ring binder
or up on the screen. Let's take a look at oh let's see I'm
sorry, I got to get the input shaft hooked up here. So here's
our input shaft from the engine. It's got the Cone clutch on it.
The Cone clutch is not applied. But I can flip this down in
Okay, so our input shaft right here connects to the Cone
clutch housing. But notice I can pull the Cone clutch housing
from rotating and still turn the input shaft. That's because this
Cone clutch is not applied. So that's the equivalent of neutral
and park. We don't have any power flow through the
transmission goes into neutral every time before it ships. Is
that the same way? No, no. It depends on the
transmission. The very few of them that actually do that. It's
called the clutch to clutch shift. The others are called
synchronous shifts and they use other pieces called them Roller
clutches in sprags. And ratchets, when we do the 6070,
the front wheel drive transaxle, it doesn't go to neutral in
between shifts. It actually completes the next
shift just one right after another without going to neutral
in between. But they're not as heavy-duty
because all those one way devices also break under heavy
load. And this is a real man's heavy-duty, the sound of
strength transmissions so they don't they take out all the
potentially weak pieces. Okay, so look at first gear, first
gear, what clutches we have to have applied for first gear.
Does everybody see we got to have the C5 clutch applied
and C1 clutch. So the C1 clutches right here, the C5
clutch is this bottom one. And so here's our output shaft,
here's our input shaft. So all I'm going to do with my hand,
I'm going to pretend I'm the C5 clutch, all I'm going to do
is come in and stop that ring gear from rotating. And then I'm
going to turn the Cone clutch housing, which is the equivalent
of this clutch being turned and connected to the engine. And it
tells us our gear ratio in first gear is 3.10. So 310 to one, so
I should have to turn this input shaft three times little more
than three times to get one full turn of the output shaft. This
rotating clutch housing has to rotate with its spline. So these
two have to turn together. So here we go. You're holding
steady, and returning these two. Yeah, so there's one. It's hard
to do with greasy fingers, too. So really, that's my first year.
I'm like really, really old truck free and attempt. So 3.1
turns the input shaft gave us one turn the output shaft, all I
did was held the C5 clutch which is the p3 ring gear from
rotating. Alright, now how do we shift to second gear. Before we
keep the Cone clutch on, if you notice, over there, it says two
main pressure, we've got the C1 clutch. So now notice that
to solenoid B, we have the C4 clutch, we'll see your C5
right here, you'll C4 here C3, C2 cone. So we
just did C5 for first gear, go to second gear, we just keep
turning the same two up here. But now we just move up one, one
set of ringers. And to go between here and here, we have
to go to neutral first, because we actually have to totally
release C5 before we apply C4 which gives us no power
flow through the transmission, which is that timing issue that
we talked about. So now second gear is 1.8 terms of the input
to one turn of the output. So here we go. Here's our output
sticker. So here's one complete turn of the input and eight
tenths of a turn. And we get second gear one 1.8 to one,
right, how do we shift to third, C3 and Cone C3 clubs.
So here's C5 C4. Now we let go of C4 and we apply C3.
And we still turn the C1 pledge. But now we've got a
gear ratio of 1.4 to one. So I'm going to hold the C4 I'm
going to turn to C1 and the rotating clutch housing
together. Notice the output shaft speeds much faster. And
now there's 1.4 to one turns. See, or Now, let's go from
fourth gear to fifth gear. What's the fifth gear ratio? No,
I'm sorry, we went from third. Let's go to fourth gear. fourth
gear ratio is one to one. So now we got to have the Cone and the
C2 clutch on. So now here's the Cone right here. Here's the
C2 right here. Notice we're not holding anything. That's
because we're in direct drive. Remember I told you in direct
drive, we don't hold anything we pick any two pieces and turn
them together. So quite simply, I grab these two pieces. And I
get one turn in equals one turn out any color two pieces or just
have to be could be these two It could be these two, any of any
of those three, we'll give you one, it's just in this
transmission. that's those are the two easiest ones. Right now
let's go to fifth gear, we have to go back and apply the C3
clutch. But now we're and hold it from rotating. But now we're
going to turn the C2 clutch housing, rather than the Cone.
Now this is overdrive, a point seven turns to the input one
turn to the output. So I'm going to hold the C3, turn the C2
and the rotating clutch housing, it's a lot harder to
turn, notice the output shaft is turning much faster. It's harder
distractors are an overdrive. Yeah. And how does it make
better fuel economy? It is only does it on nice flat roads, and
you've got an engine with a lot a lot of torque. So that's a
point seven to one, overdrive, in fifth gear, now after tooth
are beginning in 2006 model year. And by the way, this is
these are the guts out of a five speed. But let's do sixth gear
anyway, how do we get sixth gear on a 2006 and above C4,
which is this one instead of the C3 and fifth. So we're
going to keep turning the C2. But now we're going to hold the
C4. So now we'll get a point six to one overdrive ratio.
Notice it's turning much faster. But there's a point six to one
gear ratio. Right, the only gear left that we haven't done is
reverse. So how do we get reverse, C5 and C3. So
I'm going to hold C5 and hold C3. And then I'm going
to turn the rotating clutch housing that's directly
connected to the engine. So we're not using Cone or C2
at all. But notice now let's see we've got a four point 49 to one
gear ratio. Whereas now it's turning backwards. And while it
takes four and a half turns. So reverse is quite a reverse to
get us back to back to one full turn. So now
just a couple of things to get finished up with this planetary
gearset demo, I want all of you to be able to do that same thing
that I just did. First put all of these pieces together just
like I put them together, feel free to come up and look at
this, how it's assembled. But then I want you to have me come
around and verify that you know how each gear is obtained. But
let's talk troubleshooting here for a minute. What if the
C1 clutch never worked? What if it? What if it didn't work?
First? Or what could be in trouble? Everything that it's
used in on that chart, every gear it's used in would not
work? Does that make sense? spinning you can figure out
what's wrong? Yeah. would reverse work? Yeah. It would
Because see, one is not used in reverse. Only C5 and C3. When is it first? And fourth?
Don't worry. The customer is not going to come in and go I can
get it up the fifth by starving or would have just jumped in?
they would they would complain that the vehicle won't move.
Okay. So if you had the C2 clutch pack go bad don't they
would say it won't go into fourth, exactly. So if C1 were bad we'd have
first, second and third, but not for fifth or sixth. But notice
reverse would still work. Because C3 and C5 are
used for reverse. But now let's talk about C3. And this is
a common failure on a lot of transmissions. Not particularly
the Allison but what if the C3 clutch failed? What gears
would not work? reverse third and fifth. So if anyone says my
reverse doesn't work, you want to also go drive it and see does
third also not work? Because that is a diagnostic. It's a
it's the same clutch that's required for both of them. And
you want to have an idea of what's wrong with the
transmission before you take it apart. Yeah, that the transmission department
next week is the one out of like a traverse right? That the there
was a tsp where the plane is no reverse. And so we would lock it
out of those gears and that's why because a clutch pack that
wave plays a common clutch
pack to something else. All right, let's look at C4. If
C4 didn't work, we would not have second or six and then the
big one, C5 e See five didn't work with the vehicle
move at all, forward or reverse? No way. So if the vehicle doesn't
move at all, C5 is probably not working for whatever reason.
However, you cannot assume that it's inside the transmission. It
could be an electrical problem. It could be hydraulic, it could
be mechanical. But you know that something related to the C5
is the only thing that can prevent you from reverse. And
first, assuming that hydraulic presses are still okay, and so
on. So, one more time, planetary gearsets I don't care who makes
the transmission. They all have planetary gear sets, all of them
have parts that are held and turned to get different gear
ratios. All of those pieces all over your benches are either the
planetary gear sets, the clutches that hold them or turn
them, or the hydraulics and the electronics that control whether
or not they're held or turn. And that's it. So that should help
simplify in your mind all of those pieces. And of course,
putting it back together will help sequencing those pieces and
doing another transmission. When we take apart that 6070 next
week, you're going to see three more planetary gear sets but
they're going to be these little baby ones. But you'll recognize
same things planetary gear sets, clutches hydraulics electronics.
And that's it. So that's why I say if you can understand this
transmission, which is the easiest one to learn, the rest
of them come much more easily. Alright, let's get to work.
