Speaker 1: Welcome to text Stuff, a production from my Heart Radio.
Speaker 1: Hey there, and welcome to text Stuff. I'm your host,
Speaker 1: Jonathan Strickland. I'm an executive producer at I Heart Radio.
Speaker 1: And today it's time for another tech Stuff classic episode.
Speaker 1: This episode originally published way back on May six, two thirteen.
Speaker 1: It's called text Stuff Shifts into High Gear. And in
Speaker 1: this episode you can hear me and my former co host,
Speaker 1: Lauren Vogelbaum, who now hosts stuff like Savor and brain Stuff,
Speaker 1: as we try to explain how transmissions work. Let's a
Speaker 1: shift into it, shall we. So what are we talking
Speaker 1: about with transmissions? What are transmissions? Why are they necessary?
Speaker 1: What's the deal? Well, first, we have to understand that
Speaker 1: a vehicle, let's say a vehicle with an internal combustion engine,
Speaker 1: gets its power from the engine itself. Right, You're burning
Speaker 1: fuel within that engine, and that engine is putting out
Speaker 1: power in the form of kinetic energy. Now, the trick is,
Speaker 1: how do you make the kinetic energy that's generated by
Speaker 1: the engine make your vehicle move as opposed to just
Speaker 1: making noise or heat or explosions. That would be an
Speaker 1: external combustion engine not a good thing, not as useful
Speaker 1: emotion vehicles. Now, so, uh, what what's generally going on
Speaker 1: with a vehicle we're gonna take for this podcast. We're
Speaker 1: gonna specifically focus on a five speed manual transmission vehicle
Speaker 1: that has rear wheel drive. Now, there are a lot
Speaker 1: of different configurations you can have. The basic premise of
Speaker 1: the transmission is the same in all of these, but
Speaker 1: the way it's laid out is completely different depending upon
Speaker 1: the car's configuration. So this just for the purposes of
Speaker 1: this podcast, because we can't cover everything. It would be
Speaker 1: a four hour long pot least, and we we'd eventually
Speaker 1: say I don't even know where I am anymore. We're
Speaker 1: gonna keep it fairly simple. So, really, the transmission is
Speaker 1: important for being able to take the power that's an
Speaker 1: engine is generating and convert that into the kinetic energy
Speaker 1: that's necessary to get your vehicle moving. But before we
Speaker 1: get too far into that, let's kind of look back
Speaker 1: at why is a transmission even necessary? I mean, not
Speaker 1: beyond the fact of what it does. Why do we
Speaker 1: need something that like a variable transmission? Why not just
Speaker 1: something that converts the energy of an engine into the
Speaker 1: rotating force of wheels moving right? And this this has
Speaker 1: something to do with with the difference between, um, the
Speaker 1: kind of energy that you want to use when you're
Speaker 1: first starting a car, when you're accelerating it from a stop,
Speaker 1: and when you're speeding up later on down the line, right,
Speaker 1: and when you're when you're reaching your top speed as well. Yeah,
Speaker 1: as it turns out, an engine only has a very
Speaker 1: narrow range at which it's opera rating with its revolutions
Speaker 1: per minute, relatively narrow range. Uh. And if our vehicles
Speaker 1: worked within that same narrow range, we'd be fine, right,
Speaker 1: if everything was ideal, If somehow the range of the
Speaker 1: engine and the range of the motion of the wheels
Speaker 1: had a one to one ratio, whether it was directly uh, analogous,
Speaker 1: or you had to have some sort of gear shift
Speaker 1: in there too, uh to adjust it, we'd be all right.
Speaker 1: We wouldn't need a transmission, But we really need a
Speaker 1: wider range. And the two things that are really important
Speaker 1: when it comes to operating vehicles for for the purposes
Speaker 1: of this conversation, our speed and torque. Okay, so, so
Speaker 1: what's so? What's what? What is torque? Torque is is
Speaker 1: you can think of it as a twisting force. It's
Speaker 1: a rotational force. So whenever you have a wheel turning, uh,
Speaker 1: it's it's powered, it's that's that's that's torque there. Or
Speaker 1: if you're using a wrench, let's say that you need
Speaker 1: to loosen or tighten al with a wrench, you're using torque.
Speaker 1: It's this rotational force. The the end of the wrench
Speaker 1: is moving in a circle and the bolt is acting
Speaker 1: as sort of the axis of this of this pit
Speaker 1: or a pivot point for this motion. Uh. That's torque.
Speaker 1: And by increasing or decreasing torque, you can it's kind
Speaker 1: of what people talk about when they're talking about the
Speaker 1: grip on the road. Um, you can have a vehicle
Speaker 1: that has really high torque uh and really low speed.
Speaker 1: You can have a vehicle has really has speed really
Speaker 1: low torque. You can have lots of different combinations here.
Speaker 1: So for example, imagine a giant crane that you would
Speaker 1: use in a construction field. All right, so it's enormous
Speaker 1: and it's using wheels, not not treads or whatever. Uh,
Speaker 1: this vehicle is going to have an enormous amount of
Speaker 1: torque applied to the wheels in order to move this
Speaker 1: massive vehicle around. It may not be moving quickly but
Speaker 1: the torque is really powerful, which means that it would
Speaker 1: require a lot of force to make sure that those
Speaker 1: wheels don't turn. If the engine were operational and it
Speaker 1: was being put into drive, if you were trying to
Speaker 1: hold those wheels still, you would have to use an
Speaker 1: enormous amount of force to counteract that torque. You could
Speaker 1: also have a toy, let's say that has a little
Speaker 1: spinning element to it that spins at an incredible rpm,
Speaker 1: but it doesn't do so very with very much torque
Speaker 1: at all. So if you just touched it, it would
Speaker 1: stop spinning, and it would just be the lightest touch
Speaker 1: to counteract that torque. Again, the torque is not very
Speaker 1: strong with that particular device. So when we're operating our vehicles,
Speaker 1: we actually need a fairly wide range of torque, which
Speaker 1: is not something that would be possible if we had
Speaker 1: to work within the narrow parameters of what an engine
Speaker 1: is able to put out with that range of RPMs. Right,
Speaker 1: if an engine only had one speed, it would get
Speaker 1: really messy, really fast, right and exactly, And you know,
Speaker 1: the vehicle might operate fine in certain conditions, but if
Speaker 1: you change those conditions at all, then you'd be in trouble.
Speaker 1: And see that's the the issue, right because we all
Speaker 1: know when you're out there driving, not everything is a
Speaker 1: perfectly flat highway. You know you're going to have inclines,
Speaker 1: you're gonna have changes in the in the environmental conditions
Speaker 1: that are going to require your vehicle to adjust as
Speaker 1: you are going through them. So that's why you need
Speaker 1: to have a transmission. You have to have something where
Speaker 1: you can shift to a different torque or speed in
Speaker 1: order to one maintain your grip on the road and
Speaker 1: continue moving at the appropriate speed and to operate within
Speaker 1: the engine's parameters. That's one of those reasons why, Like
Speaker 1: if you keep revving the engine and you're in first gear,
Speaker 1: you'll see that needle go all the way into the
Speaker 1: red and then if you keep that up, you burn
Speaker 1: out your engine. So by shifting, you are actually adjusting
Speaker 1: torque and speed and by doing that you can keep
Speaker 1: the needle in the the ideal operational So that's what
Speaker 1: the transmission is for. It's for keeping you in this
Speaker 1: in the sweet spot. And there are of course manual transmissions,
Speaker 1: automatic transmissions, there are variants of those UM and UH.
Speaker 1: And while we're really focusing on manual transmissions. If we
Speaker 1: were to talk about automatic I think I would have
Speaker 1: to call someone else in because we would need scotten here,
Speaker 1: because it's a little bit beyond what we are certainly
Speaker 1: our personal technical level with the automotive industry. Not to
Speaker 1: mention the fact that I don't know how I would
Speaker 1: explain it in words without the benefit of pictures. It's
Speaker 1: already given me an interpretive dance, and that works less
Speaker 1: well on podcasts. You might you might hear us like
Speaker 1: with by the microphone, but it kind of loses something
Speaker 1: in the translation. Right. But so, originally automobiles only had
Speaker 1: two forward gears in one reverse. So, but they're the
Speaker 1: engine capacity was much less so so those narrow ranges
Speaker 1: were kind of okay within two gears. UM. Around the
Speaker 1: early nineteen forties late nineteen thirties, um Ford and Chrysler
Speaker 1: started introducing semi automatic gears that would let you UM.
Speaker 1: You still had to use a clutch, but you could,
Speaker 1: but you could switch between them between the higher gear
Speaker 1: semi automatically. UM. In the nineteen fifties, the first full
Speaker 1: automatics were debuted and UH and then after that all
Speaker 1: of the advances have been in the in the number
Speaker 1: of speeds, the number of gears that are involved in
Speaker 1: these transmissions. So we went from we went from two
Speaker 1: up to uh four speed manuals, and then six speed
Speaker 1: manuals started hitting the market in the late nineteen eighties, right, So, uh,
Speaker 1: and you I wonder why do you have why why
Speaker 1: do you add more of those divisions, more of those speeds.
Speaker 1: It doesn't necessarily mean that the vehicle is going to
Speaker 1: go faster than earlier vehicles. It does mean that the
Speaker 1: transitions between between the different speeds or the different gears
Speaker 1: becomes a little more smooth because you've you've refined them,
Speaker 1: You've you've made it a little more precise, all right.
Speaker 1: It lets the engines work less hard at the specific
Speaker 1: task that you were asking them to do at the time.
Speaker 1: Along these lines, just just about a couple of days ago,
Speaker 1: as of the recording of this podcast, admit a GM
Speaker 1: and four general motors of course, and Ford announced that
Speaker 1: they're going to to work together to develop nine and
Speaker 1: ten speed transmissions. I'm assuming those are automatic transmissions at
Speaker 1: this point, because that sounds like a very large gearshift
Speaker 1: that will you know, for for consumer vehicles, and that
Speaker 1: will uh, you know, save gas mileage. It could it
Speaker 1: could raise gas mileage by five to ten percent, which is,
Speaker 1: you know, not not insignificant, right, and then you're talking
Speaker 1: about decreased environmental impact. There are a lot of other
Speaker 1: benefits that roll out through these, uh some people might
Speaker 1: call them small evolutionary changes, but they can make a
Speaker 1: big difference down the road. Did not mean to do
Speaker 1: a pun there on the accidental puns. We don't. We
Speaker 1: don't need any of those mean to do it, all right,
Speaker 1: So so you might be thinking, all right, how does
Speaker 1: this whole torque shifting thing work? And we're going to
Speaker 1: get into the actual mechanics literally of it in a
Speaker 1: little bit, but in general, think of two gears. Right,
Speaker 1: If you have two gears of the same size and
Speaker 1: they are they have teeth that interlock. When you turn
Speaker 1: one gear, the other gear is going to turn at
Speaker 1: that same rate. It's going to be the same number
Speaker 1: of revolutions per minute because they are the same size,
Speaker 1: same same number of teeth, all that kind of stuff. Now,
Speaker 1: let's say that you have a large gear and a
Speaker 1: smaller gear and they are interlocking, and you're turning the
Speaker 1: large gear, that smaller gear is going to do more
Speaker 1: revolutions per minute than the large gear. You know, when
Speaker 1: you go from the starting point all the way back
Speaker 1: around to the starting point in the large gear, the
Speaker 1: small one may have turned three or four times, depending
Speaker 1: upon the ratio between the two. Right, same thing, If
Speaker 1: you have a small gear and a large gear and
Speaker 1: you're turning the small gear, you're gonna have to turn
Speaker 1: that small gear several times large gear to right exactly.
Speaker 1: And and these these differences in speed also result in
Speaker 1: a difference in torque. So that's what's going to become
Speaker 1: important when we start talking about the actual process of
Speaker 1: shifting and what is going on with the transmission. For
Speaker 1: us to understand that, we're really gonna have to take
Speaker 1: a look at the entire drive train of a vehicle,
Speaker 1: which is both exciting and intimidating to me. I think, so,
Speaker 1: I think it's really cool. It's this is this is
Speaker 1: really entertaining physics to me because I have I have,
Speaker 1: I mean, Jonathan doesn't really drive. No, Jonathan doesn't drive.
Speaker 1: Don't don't even bother putting the word really in there.
Speaker 1: Jonathan does not drive. We we fortunately have a limitedly
Speaker 1: robust public transports. I can Atlanta, I can get generally
Speaker 1: to where I need to go. Um uh, and I
Speaker 1: do drive, but I'm a very I'm not I'm not
Speaker 1: particularly a car person, so but this isn't so this
Speaker 1: is going to be an exciting Yes. I will ask
Speaker 1: Lauren about her experiences with manual transmissions later on in
Speaker 1: the podcast, so stay tuned to find out about Lauren's
Speaker 1: own personal adventures with this technology. Guys, we're gonna pop
Speaker 1: this podcast into neutral for a second so that we
Speaker 1: can take a break to thank our sponsors. All right,
Speaker 1: let's get back to how transmissions actually work. So to
Speaker 1: do this, we have to look at the entire system
Speaker 1: that makes the car go. All right, and you're you're
Speaker 1: only interacting in this five speed manual transmission that we
Speaker 1: were talking about with with two bits about the clutch
Speaker 1: and the gearshift. Yeah yeah, but but there's a lot
Speaker 1: going on under this, Yes, a whole lot. And so
Speaker 1: first we need to just understand what these what these
Speaker 1: different parts are. So you've got your car's engine, this
Speaker 1: is the thing that makes it go. Ultimately, as you
Speaker 1: are depressing the gas pedal, you are putting in more
Speaker 1: fuel to the engine, which is then generating more uh power.
Speaker 1: It creates more kinetic energy in the form of the
Speaker 1: pistons moving up and down. Those pistons are connected to
Speaker 1: a crank shaft, which converts the reciprocating motion that's the
Speaker 1: up and down motion of the pistons, into rotary motion,
Speaker 1: meaning it's turning into turning in a circular pattern. Now,
Speaker 1: so the crank shaft goes from the up down motion
Speaker 1: to the rotation motion, which is the very basis of
Speaker 1: everything else that's going to happen. Now, the crank shaft
Speaker 1: connects to a flywheel. Now, the fly wheel transmits this
Speaker 1: rotary rotary motion to a clutch plate, and the clutch
Speaker 1: plate is what eventually connects to that clutch pedal. Yeah. Yeah,
Speaker 1: In fact, there's a pressure plate that is pressed up
Speaker 1: against the clutch plate, right. So the pressure plate, when
Speaker 1: it's in contact with the clutch plate, allows this rotary
Speaker 1: motion to transmit through the rest of the of the
Speaker 1: vehicle's drive strain. So when these two things are in
Speaker 1: contact with one another, uh, as long as the engine
Speaker 1: is going, then there is some sort of rotation being
Speaker 1: transmitted at that point, assuming you're not in just a
Speaker 1: neutral So what happens when you hit the clutch, Well,
Speaker 1: When you hit the clutch, the pressure plate rises up
Speaker 1: off of lifts off the clutch plate. Once the pressure
Speaker 1: plates separates from the clutch plate, all power is cut
Speaker 1: off to the list of the transmission, the rest of
Speaker 1: the transmission exactly. So so while the engine is still going, uh,
Speaker 1: it is not providing rotary force to the transmission and wheels,
Speaker 1: which is what allows you to shift gears exactly without
Speaker 1: making things explode. All right, this is why you why
Speaker 1: if you're driving a manual, you know, you're driving stick,
Speaker 1: you have to hit the clutch first, because that ends
Speaker 1: up pulling that pressure plate off so that you are
Speaker 1: able to shift gears without making the horrible grinding noise
Speaker 1: and destroying your big brother's vehicle. Uh. I say big
Speaker 1: brother because I know a guy who did do that. Yeah, yeah,
Speaker 1: I was not there, thankfully. So, assuming that the clutch
Speaker 1: plate and pressure plate are in contact with one another,
Speaker 1: you you have not just hit the clutch um it
Speaker 1: has been providing the a rotary motion to the gearbox shaft. Now,
Speaker 1: the gearbox consists of several parts itself. You've got the
Speaker 1: main well, You've got a lay shaft which is connected
Speaker 1: to that gearbox shaft. You've got a main shaft and
Speaker 1: you've got several gears attached to both. You also have
Speaker 1: something that's either called a dog clutch or a collar,
Speaker 1: depending upon who you're talking to, and that is what
Speaker 1: is connected to a selector mechanism, which in the case
Speaker 1: of most vehicles, we think of as the stick shaft
Speaker 1: the manual shift. So, uh, the lay shaft is has
Speaker 1: got gears that are actually part of that shaft. They're
Speaker 1: they're they're spline spleened. Spleened is probably not the correct pronunciation.
Speaker 1: I'm going to a sayment's splind directly to the cheft.
Speaker 1: In other words, it's got a direct attachment. So as
Speaker 1: the chaft turns, so do the gears. Those gears have
Speaker 1: teeth along the edges and they interlocke with gears that
Speaker 1: are on the main shaft. But here's the big difference
Speaker 1: between the gears on the lay shaft and the ones
Speaker 1: on the main shaft. The gears on the main shaft
Speaker 1: are mounted on ball bearings, so they can spend freely
Speaker 1: around the axis of the main shaft without actually turning
Speaker 1: the main shift right. They're just kind of ghosting along
Speaker 1: over it until they become connected to the shaft through
Speaker 1: another piece of technology. Yeah, that would be the collar
Speaker 1: or dog clutch. Now, this is attached directly to the
Speaker 1: main shaft. It can slide to the left or right
Speaker 1: along the main shaft, but if it turns, the main
Speaker 1: shaft turns. So by interlocking the collar with the side
Speaker 1: of one of these main shaft gears, both both the
Speaker 1: collar and the main shaft gears have teeth have teeth
Speaker 1: along the sides of them so that they can interlock. Yeah, exactly. So,
Speaker 1: so imagine that I think of it this way. You've
Speaker 1: got a gear that's got teeth along the outer edge,
Speaker 1: like a like you would see in a typical gear,
Speaker 1: but you also have if you're looking at it from
Speaker 1: from one of the sides, so you're not looking at
Speaker 1: it headlong. You've turned it sideways, so you're looking at
Speaker 1: it like like a plate you're holding it up, it
Speaker 1: would have teeth and holes along the surface that you're
Speaker 1: actually looking at, and those interlock with the collar or
Speaker 1: dog clutch. Right, they kind of sandwich together. Right, So
Speaker 1: what happens is the lay shaft gears turn. That makes
Speaker 1: the main shaft gears turn, and if the collar is
Speaker 1: is engaged in that particular main shaft gear. Then the
Speaker 1: main shaft turns. I know, it sounds really confusing. It's
Speaker 1: a little difficult to get across without having visual effects.
Speaker 1: We will, by the way link on Facebook two pictures
Speaker 1: and videos of this, so it makes it easier to
Speaker 1: to to visualize and understand. But once you've got that
Speaker 1: main shaft turning, that's what then provides rotary motion to
Speaker 1: the differential. The differentials job is to to turn that
Speaker 1: rotary emotion ninety degrees because at this point, before you
Speaker 1: hit the differential, that rotation is perpendicular to the wheels,
Speaker 1: which would not work. You wouldn't get the wheels to
Speaker 1: turn that way. Not very useful. Now, yeah, you have
Speaker 1: to turn that rot rotation, that motion to be parallel
Speaker 1: with the wheels in order to get them to turn.
Speaker 1: So you can go forward or backward, depending upon which
Speaker 1: gear is is engaged. So the differential is a set
Speaker 1: of gears that transmits this ninety degrees, so you can
Speaker 1: do that again. This is your basic five speed manual
Speaker 1: transmission with rear wheel drive. So that's the basic layout.
Speaker 1: But what's going on with the transmission alright? So remember
Speaker 1: I said that you had the lay shaft and the
Speaker 1: main shaft, both of which have gears on them. So
Speaker 1: imagine that the lay shaft gears are set up so
Speaker 1: it's gears that are increasing in size as you go
Speaker 1: from gear one to gear five, and then you have
Speaker 1: your Your final gear on that shaft is for reverse.
Speaker 1: It's about the same size as the one that's going
Speaker 1: to be on the main shaft. Along the main shaft,
Speaker 1: of course, the gears are going to be in reverse
Speaker 1: order of size. So for the small lay shaft gear,
Speaker 1: you have a large main shaft gear, The next main
Speaker 1: shaft gear is a little smaller, the next one a
Speaker 1: little smaller, and a little smaller, so by the time
Speaker 1: you get to fifth gear, you've got a large lay
Speaker 1: shaft gear and a small main shaft gear. This is
Speaker 1: all because of that that relationship between speed and torque
Speaker 1: I was talking about. So if you've got a small
Speaker 1: lay shaft gear turning a large main shaft gear, that
Speaker 1: means that the larger main shaft gear has more torque
Speaker 1: but less speed. So that's important when you are accelerating
Speaker 1: from a stop so your car has not started moving,
Speaker 1: you want to engage that small gear on the lay
Speaker 1: shaft to turn the large gear on the main shaft
Speaker 1: so that you will start to accelerate from a stopped position. Now,
Speaker 1: once you start speeding up, you are eventually going to
Speaker 1: require the engine to do more power, more work than
Speaker 1: what it is comfortable doing. That's when you need to
Speaker 1: shift to second gear, which will be a decrease in
Speaker 1: torque but an increase in speed. And it's because that
Speaker 1: gear ratio has changed. The lay shaft gear is a
Speaker 1: little larger for gear too, and the main shaft gears
Speaker 1: a little smaller for gear too. That's where you get
Speaker 1: that change in torque and speed. And this is true
Speaker 1: for for each speed step up, for each gear step up. Yeah, exactly.
Speaker 1: So once you get up to gear five, that's when
Speaker 1: you're going really really fast, but I don't know, yeah,
Speaker 1: about as fast as the engine can can hand out
Speaker 1: without you know, having you drive off a cliff dukes
Speaker 1: of Hazzard style, in which case gravity takes control in
Speaker 1: your acceleration is completely dependent upon that. But that's the
Speaker 1: general progression we're getting towards the end. But before we
Speaker 1: actually do shift into high gear, let's take another quick break.
Speaker 1: So if you're looking at how does the power flow
Speaker 1: I'll walk you through it one more time. So power
Speaker 1: goes like this engine to pistons, pistons to crankshaft, crank
Speaker 1: shaft to fly with will fly wheel to gear shaft,
Speaker 1: gear cheft to lay shaft, lay cheft to lay shaft gears,
Speaker 1: lay shaft gears to main shaft gears, main shift gears
Speaker 1: to the dog clutch or collar color to main shaft,
Speaker 1: main cheft to differential, differential to wheels, and the wheels
Speaker 1: on the bus go round and round. Alternately, the red
Speaker 1: things connected to my wristwatch. Yeah, there you go. And so, uh,
Speaker 1: when when you are shifting gears, what's actually happening is
Speaker 1: again you hit the clutch. It then separates the power
Speaker 1: of the engine from the from the gearbox down the line.
Speaker 1: So that allows you to move the collar or dog
Speaker 1: clutch from one of those gears to another. And if
Speaker 1: you if you want to visualize and imagine that you've
Speaker 1: got a horizontal pole and you've got gears going from
Speaker 1: the largest to the smallest end in reverse, which is
Speaker 1: kind of a medium sized gear. I'll get the reverse
Speaker 1: in a minute, because that one's kind of interesting, like
Speaker 1: how do you make it go backwards? You might say, well, um,
Speaker 1: you've got uh, this this range of gears. Between each
Speaker 1: set of two, you've got one of those dog clutches
Speaker 1: or collars that's directly attached to the main shaft, all right,
Speaker 1: so that that collar can move to the left or
Speaker 1: right along this horizontal pole and engage either of the
Speaker 1: two gears that are on either side of it. And there, yeah,
Speaker 1: there's set of these in a in a manual five speed,
Speaker 1: there's going to be three of these collars, right because
Speaker 1: between gears one and two, gears three and four, and
Speaker 1: gears five and reverse, or you know, whatever configuration there are,
Speaker 1: that's that's where the collars would be and they would
Speaker 1: be able to engage either of the two, whichever one
Speaker 1: on either side. So if you're in gear number one
Speaker 1: and you're speeding up to gear number two, you hit
Speaker 1: the clutch, the pressure plate comes off, the clutch plate.
Speaker 1: Power is cut off to the from the engine to
Speaker 1: the transmission exactly. Uh. And then as you shift the
Speaker 1: gear shift from one to two, the dog color disengages
Speaker 1: from one and moves into the gear to locks in place.
Speaker 1: By that time, you've you've left of the clutch and
Speaker 1: the power gets re engaged and it just starts turning,
Speaker 1: or it allows that main gear, that main shift gear
Speaker 1: to turn. That dog collar at that point point is decreased,
Speaker 1: speed is increased. Yes, um and uh. And that is
Speaker 1: the grinding that you hear. Actually, if you miss shift,
Speaker 1: it's going to be the teeth on the side of
Speaker 1: the collar against the teeth on the side of the
Speaker 1: main shaft gear that it's trying and failing. Has nothing
Speaker 1: to do with the lay shaft. That's always going to
Speaker 1: lay shaft and main and main shaft gears are always
Speaker 1: going to be turning at the same general speed depending
Speaker 1: upon how much power you're giving the engine. They are not.
Speaker 1: It has nothing to do with the lay shaft at all.
Speaker 1: It's just that main shaft gear. Although in originally in
Speaker 1: manual transmissions they were called sliding gear transmissions, and the
Speaker 1: main shaft gears were in fact blind to the main
Speaker 1: shaft so so they weren't on those ball bearings, they
Speaker 1: weren't floating along it so um, which which meant that
Speaker 1: the grinding noise that you would hear in those originals
Speaker 1: was in fact the teeth of the main shaft gears
Speaker 1: failing to line up and grinding against the lay shaft gears.
Speaker 1: I would imagine you would only have one lay shaft
Speaker 1: gear and you would have variable main shaft gear sizes,
Speaker 1: and that's what would you know? It would just shift
Speaker 1: along those That's how I would imagine that would work.
Speaker 1: Of course I don't know because I didn't look into that.
Speaker 1: But that's that's my first reaction, based upon how how
Speaker 1: the typical five speed manual transmission car works. I didn't
Speaker 1: look that deeply into it, so I can I can
Speaker 1: neither confirm nor deny. I'm sure one of my listeners
Speaker 1: will take me to task and explain how I got
Speaker 1: that completely wrong. Those just me guessing from based upon
Speaker 1: my understanding of the other the other method. So so reverse,
Speaker 1: how does reverse work? Reverse is interesting because you actually
Speaker 1: have three gears, not just the two, Not just the
Speaker 1: lay shaft gear and the main shaft gear. There's a
Speaker 1: tiny little gear in between them called the idler gear. Now,
Speaker 1: because you have a third gear there that's in between
Speaker 1: two gears, you actually reverse the rotational direction for the
Speaker 1: main shaft gear. So while all the other let's let's
Speaker 1: use you know, clockwise and counterclockwise, while all the other
Speaker 1: main shaft gears maybe turning in a clockwise motion based
Speaker 1: upon your perspective, the reverse one will be moving in
Speaker 1: a counterclockwise motion. Or winter Shans for my Shakespearean friends.
Speaker 1: Because that other, that tiny little gear, is all that
Speaker 1: needs to happen to h to reverse that motion. This
Speaker 1: is easy to see if you ever have gears just
Speaker 1: to play with. So if you interlock two gears and
Speaker 1: you and you turn them, you'll see that based upon
Speaker 1: the rotation of one, the rotation the other is always
Speaker 1: going to be the same. When you put a another
Speaker 1: gear between them and you turn the first one the
Speaker 1: third one, the third gear that used to be the
Speaker 1: second gear is now turning in the opposite direction as
Speaker 1: it did before, because you've got that that intermediary gear,
Speaker 1: the idler gear. So that's what hams when you switch
Speaker 1: into reverse. It uh, the coller engages with the main
Speaker 1: shaft gear that is being turned by this idler gear
Speaker 1: that in turn is being turned by the lay shaft gear.
Speaker 1: And to everything turn, turn, turn, there's ask your parents,
Speaker 1: all right. So that's that's the basis for manual transmission.
Speaker 1: Automatic transmission is a little a lot more complicated because
Speaker 1: we would be talking about planetary gears, which include and
Speaker 1: I'm not making this up for people who are unfamiliar
Speaker 1: with it includes a planet gear, a sun gear, and
Speaker 1: a ring gear. But it's all incorporated into one component,
Speaker 1: and it it might as well be magic. Uh, it
Speaker 1: is beyond my ken. I know that Scott understands it
Speaker 1: backwards and forwards, and if he were in this room
Speaker 1: right now, he would just be quietly chuckling to himself,
Speaker 1: not in a mean way, just in his yeah, it's
Speaker 1: so cute that you're trying kind of way. But now
Speaker 1: comes to the important part of our podcast, Lauren, I
Speaker 1: want to know about your experiences driving a stick shift car,
Speaker 1: because I have none. Yeah. Yeah, the well, I've I've
Speaker 1: never um done a whole lot of time driving stick
Speaker 1: shift cars. This is a very brief series of lessons
Speaker 1: that I received from from from one of the first
Speaker 1: people that I dated, Bob, who was a big car
Speaker 1: enthusiast and was really keen on teaching me how to
Speaker 1: drive stick And so the first time that I got
Speaker 1: into this, yeah, I had driven, I'd driven automatics before,
Speaker 1: so I was I was passingly familiar anyway with how
Speaker 1: cars worked. But but I got in and I sat
Speaker 1: down and he was like, all right, well you're a
Speaker 1: neutral so um, so you're gonna want to disengage the clutch.
Speaker 1: And I was like, clutch where this was where Bob
Speaker 1: learns that perhaps there's a preliminary lesson that needs to
Speaker 1: be taught before the practical Yeah, it was, it was,
Speaker 1: it was. It was a slow start. Well, I have
Speaker 1: to admit, like I used to a friend of mine,
Speaker 1: every now and then we get a chance to drive
Speaker 1: his mother's car, and his mother's car was a manual transmission,
Speaker 1: and I used to take both delight and genuine terror, uh,
Speaker 1: the experience of screaming whenever he would start to pull
Speaker 1: out of our high school parking lot and halfway through
Speaker 1: the turn the car starts to stall out because he's
Speaker 1: not Yeah, he's not handling the car properly. Right. There's
Speaker 1: when when when you press the clutch, there's this you um,
Speaker 1: you can feel when it engages and disengages and um,
Speaker 1: and you have to pay very close attention. I've noticed
Speaker 1: anyway in the cars that I've driven to to where
Speaker 1: that is. And that's when you can use the gear
Speaker 1: shift and if you miss it, then you either stall
Speaker 1: out or you get that terrible grinding noise and you're
Speaker 1: lucky both, right, Yeah, and that is that is a
Speaker 1: thing that I'm really I'm really awful at. I could.
Speaker 1: I could always I was fine driving out highways when
Speaker 1: I could kind of just go up to I haven't
Speaker 1: hang out there for a long time. But but once
Speaker 1: we got back into into town, I would be like,
Speaker 1: you know what, I'm going to pull over into the
Speaker 1: first gas station, set it into neutral and just like
Speaker 1: leap screaming from the car and allow somebody with more
Speaker 1: experience to handle. Alright, note to self. Alright, so uh yeah,
Speaker 1: I mean and of course people there are people who
Speaker 1: genuinely love drying driving manual transmission cars because they have
Speaker 1: that sense of they've got even more control over the vehicles. Yeah,
Speaker 1: and you really can feel I mean, I I understand.
Speaker 1: It's fun. I mean, it's it's it's fun to to
Speaker 1: get to to get to move stuff around and you
Speaker 1: feel like you're a crazy action here and you can
Speaker 1: feel the road better and you feel like you do
Speaker 1: have more control over what the engine is doing. That
Speaker 1: wraps up another classic episode of tech stuff. Hope you
Speaker 1: guys enjoyed it. If you have any suggestions for future
Speaker 1: episode topics. Let me know by reaching out on Facebook
Speaker 1: or Twitter. The handle we use it both is text
Speaker 1: stuff h s W and I'll talk to you again
Speaker 1: really soon m hm. Text Stuff is an I Heart
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