WEBVTT - CLASSIC: What Do Transmissions Do? 0:00:04.240 --> 0:00:07.920 Get in touch with technology with text Stuff from Stuff stat. 0:00:11.480 --> 0:00:13.600 Hey there, guys, and welcome to tech Stuff. This is 0:00:13.680 --> 0:00:16.800 Jonathan Strickland, and today we're gonna look back on a 0:00:16.880 --> 0:00:20.480 classic episode of tech Stuff. This is one that Lauren 0:00:20.560 --> 0:00:24.280 Vogel Baumb was on and it's all about transmissions. It's 0:00:24.320 --> 0:00:28.200 called what do Transmissions Do? And since Scott came in 0:00:28.240 --> 0:00:31.040 and we did an episode about electric bikes and we 0:00:31.080 --> 0:00:33.600 talked a bit about gear systems, I thought it would, 0:00:33.960 --> 0:00:37.599 you know, benefit us to revisit transmissions and understand how 0:00:37.720 --> 0:00:41.600 gears help us with our automobiles. So I hope you enjoyed. 0:00:47.800 --> 0:00:51.159 So what are we talking about with transmissions? What are transmissions? 0:00:51.240 --> 0:00:55.640 Why are they necessary? What's the deal? Well, first we 0:00:55.680 --> 0:00:59.800 have to understand that a vehicle, let's say a vehicle 0:00:59.840 --> 0:01:03.360 with an internal combustion engine, gets its power from the 0:01:03.360 --> 0:01:06.480 engine itself. Right, You're burning fuel within that engine and 0:01:06.520 --> 0:01:08.080 that engine is putting out power in the form of 0:01:08.120 --> 0:01:12.320 kinetic energy. Now, the trick is how do you make 0:01:12.319 --> 0:01:15.080 the kinetic energy that's generated by the engine make your 0:01:15.160 --> 0:01:18.720 vehicle move as opposed to just making noise or heat 0:01:19.080 --> 0:01:23.080 or explosions that would be an external combustion engine not 0:01:23.200 --> 0:01:28.600 a good thing. Not vehicles. Now, so, uh, what what's 0:01:28.720 --> 0:01:32.480 generally going on with a vehicle we're gonna take for 0:01:32.520 --> 0:01:36.600 this podcast. We're gonna specifically focus on a five speed 0:01:37.160 --> 0:01:41.679 manual transmission vehicle that has rear wheel drive. Now, there 0:01:41.720 --> 0:01:44.560 are a lot of different configurations you can have. The 0:01:44.600 --> 0:01:48.000 basic premise of the transmission is the same in all 0:01:48.000 --> 0:01:50.080 of these, but the way it's laid out is completely 0:01:50.080 --> 0:01:53.520 different depending upon the car's configuration. So this just for 0:01:53.560 --> 0:01:55.960 the purposes of this podcast, because we can't cover everything. 0:01:56.000 --> 0:01:58.840 It would be a four hour long pod least, and 0:01:58.960 --> 0:02:01.680 we we we'd have actually say I don't even know 0:02:01.720 --> 0:02:05.440 where I am anymore. We're gonna keep it fairly simple. So, really, 0:02:05.920 --> 0:02:09.840 the transmission is important for being able to take the 0:02:09.880 --> 0:02:12.560 power that an engine is generating and convert that into 0:02:12.600 --> 0:02:15.920 the kinetic energy that's necessary to get your vehicle moving. 0:02:16.240 --> 0:02:19.320 But before we get too far into that, let's kind 0:02:19.320 --> 0:02:23.640 of look back at why is a transmission even necessary, 0:02:23.760 --> 0:02:25.800 I mean, not beyond the fact of what it does. 0:02:26.280 --> 0:02:29.800 Why do we need something that like a variable transmission, 0:02:29.960 --> 0:02:32.480 Why not just something that converts the energy of an 0:02:32.480 --> 0:02:37.280 engine into the rotating force of wheels moving right. And 0:02:37.320 --> 0:02:39.359 this this has something to do with with the difference 0:02:39.400 --> 0:02:41.799 between um, the kind of energy that you want to use, 0:02:41.880 --> 0:02:45.000 when you're first starting a car, when you're accelerating it 0:02:45.080 --> 0:02:49.480 from a stop, and when you're speeding up later on 0:02:49.520 --> 0:02:51.320 down the line, right, and when you're when you're reaching 0:02:51.320 --> 0:02:54.519 your top speed as well. Yeah, As it turns out, 0:02:54.840 --> 0:02:58.360 an engine only has a very narrow range at which 0:02:58.560 --> 0:03:04.280 it's operating with its revolutions per minute, relatively narrow range. Uh. 0:03:04.320 --> 0:03:07.600 And if our vehicles worked within that same narrow range, 0:03:07.880 --> 0:03:11.080 we'd be fine, right, if everything was ideal, If somehow 0:03:11.440 --> 0:03:13.840 the range of the engine and the range of the 0:03:13.880 --> 0:03:16.720 motion of the wheels had a one to one ratio, 0:03:16.840 --> 0:03:20.359 whether it was directly uh, analogous, or you had to 0:03:20.400 --> 0:03:23.079 have some sort of gear shift in there too, uh 0:03:23.160 --> 0:03:25.760 to adjust it, we'd be all right. We wouldn't need 0:03:25.800 --> 0:03:29.760 a transmission, But we really need a wider range. And 0:03:30.000 --> 0:03:32.919 the two things that are really important when it comes 0:03:32.960 --> 0:03:36.600 to operating vehicles, uh, for for the purposes of this conversation, 0:03:36.640 --> 0:03:40.400 our speed and torque. Okay, So, so what's so? What's what? 0:03:40.520 --> 0:03:44.520 What is torque? Torque is is you can think of 0:03:44.560 --> 0:03:48.440 it as a twisting force. It's a rotational force. So 0:03:48.560 --> 0:03:53.040 whenever you have a wheel turning, uh, it's it's powered, 0:03:53.280 --> 0:03:56.240 it's that's that's that's torque there. Or if you're using 0:03:56.240 --> 0:03:58.760 a wrench, let's say that you need to loosen or 0:03:58.800 --> 0:04:02.360 tighten a bolt with a inch, you're using torque. It's 0:04:02.400 --> 0:04:05.000 this rotational force. The the end of the wrench is 0:04:05.040 --> 0:04:08.000 moving in a circle and the bolt is acting as 0:04:08.040 --> 0:04:11.080 sort of the axis of this of this pit or 0:04:11.120 --> 0:04:14.560 a pivot point for this motion. Uh. That's torque. And 0:04:15.160 --> 0:04:18.560 by increasing or decreasing torque, you can it's kind of 0:04:18.560 --> 0:04:20.440 what people talk about when they're talking about the grip 0:04:20.600 --> 0:04:23.919 on the road. Um, you can have a vehicle that 0:04:24.440 --> 0:04:28.080 has really high torque uh and really low speed. You 0:04:28.120 --> 0:04:30.599 can have a vehicle has really had speed really low torque. 0:04:30.600 --> 0:04:33.320 You can have lots of different combinations here. So for example, 0:04:33.880 --> 0:04:36.800 imagine a giant crane that you would use in a 0:04:36.880 --> 0:04:41.520 construction field. All right, so it's enormous and it's using wheels, 0:04:41.520 --> 0:04:45.080 not not treads or whatever. Uh, this vehicle is going 0:04:45.120 --> 0:04:47.840 to have an enormous amount of torque applied to the 0:04:47.880 --> 0:04:51.120 wheels in order to move this massive vehicle around. It 0:04:51.160 --> 0:04:54.320 may not be moving quickly, but the torque is really powerful, 0:04:54.360 --> 0:04:57.360 which means that it would require a lot of force 0:04:57.720 --> 0:05:00.800 to make sure that those wheels don't turn earn if 0:05:00.800 --> 0:05:03.719 the engine were operational and it was being put into drive. 0:05:04.040 --> 0:05:05.960 So if you were trying to hold those wheels still, 0:05:06.040 --> 0:05:08.120 you would have to use an enormous amount of force 0:05:08.160 --> 0:05:12.320 to counteract that torque. You could also have a toy, 0:05:12.640 --> 0:05:14.880 let's say that has a little spinning element to it 0:05:14.920 --> 0:05:18.240 that spins at an incredible rpm, but it doesn't do 0:05:18.360 --> 0:05:20.880 so very with very much torque at all. So if 0:05:20.920 --> 0:05:24.000 you just touched it, it would stop spinning, and it 0:05:24.040 --> 0:05:26.919 would just be the lightest touch to counteract that torque. Again, 0:05:26.960 --> 0:05:30.600 the torque is not very strong with that particular device. 0:05:31.120 --> 0:05:34.000 So when we're operating our vehicles, we actually need a 0:05:34.040 --> 0:05:38.000 fairly wide range of torque, which is not something that 0:05:38.040 --> 0:05:40.720 would be possible if we had to work within the 0:05:40.800 --> 0:05:43.240 narrow parameters of what an engine is able to put 0:05:43.240 --> 0:05:45.479 out with that range of RPMs. Right, if an engine 0:05:45.480 --> 0:05:48.680 only had one speed, and it would get really messy, 0:05:48.720 --> 0:05:51.960 really fast, right and exactly, and you know, the vehicle 0:05:52.080 --> 0:05:55.719 might operate fine in certain conditions, but if you change 0:05:55.720 --> 0:05:58.600 those conditions at all, then you'd be in trouble. And 0:05:58.640 --> 0:06:01.640 see that's the that's the issue, because we all know 0:06:01.800 --> 0:06:04.640 when you're out there driving, not everything is a perfectly 0:06:04.720 --> 0:06:07.600 flat highway. You know you're going to have inclines, you're 0:06:07.600 --> 0:06:10.839 gonna have changes in the in the environmental conditions that 0:06:10.880 --> 0:06:14.000 are going to require your vehicle to adjust as you 0:06:14.040 --> 0:06:16.080 are going through them. So that's why you need to 0:06:16.120 --> 0:06:18.560 have a transmission. You have to have something where you 0:06:18.640 --> 0:06:22.840 can shift to a different torque or speed in order 0:06:22.839 --> 0:06:26.200 to one maintain your grip on the road and continue 0:06:26.240 --> 0:06:30.160 moving at the appropriate speed and to operate within the 0:06:30.200 --> 0:06:33.400 engine's parameters. That's one of those reasons why, Like if 0:06:33.440 --> 0:06:35.520 you keep revving the engine and you're in first gear, 0:06:35.800 --> 0:06:37.560 you'll see that needle go all the way into the 0:06:37.560 --> 0:06:39.680 red and then if you keep that up, you burn 0:06:39.720 --> 0:06:43.120 out your engine. So by shifting, you are actually adjusting 0:06:43.240 --> 0:06:46.840 torque and speed and by doing that you can keep 0:06:46.920 --> 0:06:52.320 the needle in the the ideal operational So that's what 0:06:52.400 --> 0:06:54.960 the transmission is for. It's for keeping you in this 0:06:55.560 --> 0:07:00.000 in the sweet spot. And there are of course manual transmissions, 0:07:00.000 --> 0:07:04.760 automatic transmissions, there are variants of those, UM and UH 0:07:04.800 --> 0:07:07.640 and while we're really focusing on manual transmissions, if we 0:07:07.640 --> 0:07:10.400 were to talk about automatic I think I would have 0:07:10.520 --> 0:07:13.600 to call someone else in because yeah, we would need 0:07:13.640 --> 0:07:16.280 Scotten here, because it's a little bit beyond what we 0:07:16.360 --> 0:07:20.320 are certainly our personal technical level with the automotive industry. 0:07:20.360 --> 0:07:22.200 Not to mention the fact that I don't know how 0:07:22.240 --> 0:07:25.559 I would explain it in words without the benefit of pictures. 0:07:25.600 --> 0:07:28.600 It's already an interpretive dance, and that works less well 0:07:28.640 --> 0:07:31.360 on podcasts. But you might you might hear us like 0:07:31.640 --> 0:07:34.480 with by the microphone, but it kind of loses something 0:07:34.480 --> 0:07:38.120 in the translation. All right. But so, originally automobiles only 0:07:38.160 --> 0:07:41.920 had two forward gears in one reverse. So, but they're 0:07:42.320 --> 0:07:45.239 the engine capacity was much less, so so those narrow 0:07:45.360 --> 0:07:49.280 ranges were kind of okay within two gears. Um Around 0:07:49.400 --> 0:07:53.640 the early nineteen forties late nineteen thirties, um Ford and 0:07:53.720 --> 0:07:57.880 Chrysler started introducing semi automatic gears that would let you um, 0:07:58.520 --> 0:08:00.640 you still had to use a clutch, but you could, 0:08:00.640 --> 0:08:03.840 but you could switch between them between the higher gear 0:08:03.880 --> 0:08:08.400 semi automatically. In the nineteen fifties, the first full automatics 0:08:08.440 --> 0:08:10.960 were debuted and uh and then after that all of 0:08:10.960 --> 0:08:13.960 the advances have been in the in the number of speeds, 0:08:13.960 --> 0:08:16.640 the number of gears that are involved in these transmissions. 0:08:16.640 --> 0:08:19.000 So we went from we went from two up to 0:08:19.200 --> 0:08:22.280 UH four speed manuals, and then six speed manuals started 0:08:22.320 --> 0:08:25.920 hitting the market in the late nineteen eighties, right, So 0:08:26.160 --> 0:08:28.800 uh and you might wonder why do you have why 0:08:28.840 --> 0:08:31.680 why do you add more of those divisions, more of 0:08:31.720 --> 0:08:34.560 those speeds. It doesn't necessarily mean that the vehicle is 0:08:34.559 --> 0:08:37.720 going to go faster than earlier vehicles. It does mean 0:08:37.760 --> 0:08:41.040 that the transitions between between the different speeds or the 0:08:41.040 --> 0:08:44.760 different gears becomes a little more smooth because you've you've 0:08:44.920 --> 0:08:47.719 refined them, You've you've made it a little more precise. Right. 0:08:47.720 --> 0:08:51.400 It lets the engines work less hard at the specific 0:08:51.440 --> 0:08:53.280 task that you were asking them to do at the time. 0:08:53.800 --> 0:08:57.080 Along these lines, just just about a couple of days 0:08:57.080 --> 0:08:59.160 ago as of the recording of this podcast, in mid 0:08:59.200 --> 0:09:02.800 April teen GM and four General Motors of course and 0:09:02.840 --> 0:09:05.440 Ford announced that they're going to to work together to 0:09:05.559 --> 0:09:09.560 develop nine and ten speed transmissions. I'm assuming those are 0:09:09.600 --> 0:09:11.880 automatic transmissions at this point, because that sounds like a 0:09:12.000 --> 0:09:16.760 very large gearshift that will, you know, for for consumer vehicles, 0:09:16.760 --> 0:09:19.720 and that will uh, you know, save gas mileage. It 0:09:19.720 --> 0:09:22.160 could it could raise gas mileage by five to ten percent, 0:09:22.280 --> 0:09:25.160 which is you know, not no insignificant, right, and then 0:09:25.200 --> 0:09:28.120 you're talking about decreased environmental impact. There are a lot 0:09:28.160 --> 0:09:31.679 of other benefits that roll out through these, uh some 0:09:31.720 --> 0:09:34.880 people might call them small evolutionary changes, but they can 0:09:34.920 --> 0:09:38.520 make a big difference down the road. Did not mean 0:09:38.559 --> 0:09:41.520 to do a pun there one goes out the crystal edge, 0:09:41.559 --> 0:09:43.719 accidental puns. We don't we don't need any of those. 0:09:43.760 --> 0:09:45.520 Doesn't mean to do it, all right, So so you 0:09:45.600 --> 0:09:49.120 might be thinking, all right, how does this whole torque 0:09:49.280 --> 0:09:51.640 shifting thing work? And we're going to get into the 0:09:51.679 --> 0:09:55.719 actual mechanics literally of it in a little bit, but 0:09:55.880 --> 0:09:59.720 in general, think of two gears. All right. If you 0:09:59.760 --> 0:10:02.439 have two gears are the same size, and they are 0:10:02.679 --> 0:10:05.920 they have teeth that interlock. When you turn one gear, 0:10:06.160 --> 0:10:08.679 the other gear is going to turn at that same rate. 0:10:08.679 --> 0:10:10.439 It's going to be the same number of revolutions per 0:10:10.440 --> 0:10:12.680 minute because they are the same size, same same number 0:10:12.720 --> 0:10:15.600 of teeth, all that kind of stuff. Now, let's say 0:10:15.640 --> 0:10:19.480 that you have a large gear and a smaller gear 0:10:19.880 --> 0:10:22.800 and they are interlocking and you're turning the large gear, 0:10:23.040 --> 0:10:25.720 that smaller gear is going to do more revolutions per 0:10:25.880 --> 0:10:28.280 minute than the large gear. You know, when you go 0:10:28.400 --> 0:10:30.960 from the starting point all the way back around to 0:10:31.000 --> 0:10:33.080 the starting point in the large gear, the small one 0:10:33.120 --> 0:10:35.600 may have turned three or four times, depending upon the 0:10:35.720 --> 0:10:38.760 ratio between the two. Right, same thing. If you have 0:10:39.000 --> 0:10:41.240 a small gear in a large gear and you're turning 0:10:41.240 --> 0:10:43.280 the small gear, you're gonna have to turn that small 0:10:43.280 --> 0:10:47.720 gear several times, you know, large gear to right exactly. 0:10:47.760 --> 0:10:51.000 And and these these differences in speed also result in 0:10:51.040 --> 0:10:54.400 a difference in torque. So that's what's going to become 0:10:54.440 --> 0:10:57.920 important when we start talking about the actual process of 0:10:58.040 --> 0:11:02.000 shifting and what's going on with the transmission. For us 0:11:02.040 --> 0:11:03.760 to understand that, we're really gonna have to take a 0:11:03.800 --> 0:11:07.400 look at the entire drive train of a vehicle, which 0:11:07.440 --> 0:11:12.080 is both exciting and intimidating to me. I think, so, 0:11:12.120 --> 0:11:14.000 I think it's really cool. It's this is this is 0:11:14.040 --> 0:11:16.840 really entertaining physics to me, because I have I have 0:11:17.000 --> 0:11:20.760 I mean, Jonathan doesn't really drive. No, Jonathan doesn't drive. 0:11:21.000 --> 0:11:23.280 Don't don't even bother putting the word really in there. 0:11:23.360 --> 0:11:27.320 Jonathan does not drive. We wait, we fortunately have a 0:11:27.400 --> 0:11:31.480 limitedly robust public transport system. I can get land, I 0:11:31.520 --> 0:11:35.040 can get generally to where I need to go. Um uh, 0:11:35.120 --> 0:11:37.280 and I do drive. But I'm a very I'm not 0:11:37.600 --> 0:11:40.200 I'm not particularly a car person. So but this is so, 0:11:40.240 --> 0:11:42.439 this is going to be an exciting Yes. I will 0:11:42.480 --> 0:11:46.520 ask Lauren about her experiences with manual transmissions later on 0:11:46.600 --> 0:11:49.160 in the podcast, So stay tuned to find out about 0:11:49.200 --> 0:11:53.120 Lauren's own personal adventures with this technology. All right, let's 0:11:53.160 --> 0:11:56.920 get back to how transmissions actually work. So to do this, 0:11:56.960 --> 0:12:00.400 we have to look at the entire si stum that 0:12:00.480 --> 0:12:03.560 makes the car go. All right, and you're you're only 0:12:03.600 --> 0:12:06.440 interacting in this five speed manual transmission that we were 0:12:06.440 --> 0:12:09.000 talking about with with two bits of the clutch and 0:12:09.040 --> 0:12:11.760 the gearshift. Yeah yeah, but but there's a lot going 0:12:11.840 --> 0:12:15.560 on under this, Yes, a whole lot. And so first 0:12:15.640 --> 0:12:18.160 we need to just understand what these what these different 0:12:18.240 --> 0:12:22.040 parts are. So you've got your car's engine. This is 0:12:22.080 --> 0:12:26.120 the thing that makes it go. Ultimately, as you are 0:12:26.520 --> 0:12:29.480 depressing the gas pedal, you are putting in more fuel 0:12:29.559 --> 0:12:32.640 to the engine, which is then generating more uh power. 0:12:32.760 --> 0:12:35.160 It creates more kinnetic energy in the form of the 0:12:35.200 --> 0:12:39.200 pistons moving up and down. Those pistons are connected to 0:12:39.480 --> 0:12:44.240 a crank shaft, which converts the reciprocating motion that's the 0:12:44.320 --> 0:12:47.840 up and down motion of the pistons, into rotary motion, 0:12:47.880 --> 0:12:51.880 meaning it's turning into turning in a circular pattern. Now, 0:12:51.960 --> 0:12:55.360 so the crank shaft goes from the up down motion 0:12:55.360 --> 0:12:58.080 to the rotation motion, which is the very basis of 0:12:58.360 --> 0:13:02.559 everything else that's going to have. And now the crankshaft 0:13:02.920 --> 0:13:07.520 connects to a flywheel. Now, the fly wheel transmits this 0:13:07.600 --> 0:13:11.480 rotary rotary motion to a clutch plate, and the clutch 0:13:11.520 --> 0:13:15.120 plate is but eventually connects to that clutch pedal. Yeah. Yeah. 0:13:15.160 --> 0:13:17.840 In fact, there's a pressure plate that is pressed up 0:13:17.880 --> 0:13:20.520 against the clutch plate, right, So the pressure plate, when 0:13:20.559 --> 0:13:24.280 it's in contact with the clutch plate, allows this rotary 0:13:24.360 --> 0:13:27.400 motion to transmit through the rest of the of the 0:13:27.520 --> 0:13:31.320 vehicle's drivetrain. So when these two things are in contact 0:13:31.360 --> 0:13:35.319 with one another, uh, as long as the engine is going, 0:13:35.520 --> 0:13:40.520 then there is some sort of rotation being transmitted at 0:13:40.520 --> 0:13:43.600 that point, assuming you're not in just a neutral So 0:13:44.320 --> 0:13:45.920 what happens when you hit the clutch, Well, when you 0:13:46.000 --> 0:13:49.960 hit the clutch, the pressure plate rises up off of 0:13:50.360 --> 0:13:54.400 lifts off the clutch plate. Once the pressure plates separates 0:13:54.440 --> 0:13:57.880 from the clutch plate, all power is cut off to 0:13:57.960 --> 0:14:00.880 the best of the transmission, the rest of the transmission exactly. 0:14:00.920 --> 0:14:04.160 So so while the engine is still going, uh, it 0:14:04.280 --> 0:14:09.120 is not providing rotary force to the transmission and wheels, 0:14:09.240 --> 0:14:12.080 which is what allows you to shift gears exactly without 0:14:12.240 --> 0:14:14.680 making things explode. All right, this is why you why 0:14:14.720 --> 0:14:18.240 if you're driving a manual, you know, driving stick, you 0:14:18.280 --> 0:14:20.880 have to hit the clutch first, because that ends up 0:14:20.920 --> 0:14:23.200 pulling that pressure plate off so that you are able 0:14:23.240 --> 0:14:27.000 to shift gears without making the horrible grinding noise and 0:14:27.080 --> 0:14:31.080 destroying your big brother's vehicle. Uh. I say big brother, 0:14:31.120 --> 0:14:34.840 because I know a guy who did do that. Yeah, 0:14:35.040 --> 0:14:38.440 I was not there, thankfully. So assuming that the clutch 0:14:38.480 --> 0:14:40.800 plate and pressure plate are in contact with one another, 0:14:40.840 --> 0:14:43.760 you you have not just hit the clutch. Um it 0:14:43.880 --> 0:14:49.640 is then providing that rotary motion to the gearbox shaft. Now, 0:14:49.680 --> 0:14:53.520 the gearbox consists of several parts itself. You've got the 0:14:54.920 --> 0:14:57.200 main well, You've got a lay shaft which is connect 0:14:57.240 --> 0:15:00.240 to that gearbox shaft. You've got a main shaft aft 0:15:00.720 --> 0:15:04.360 and you've got several gears attached to both. You also 0:15:04.400 --> 0:15:07.560 have something that's either called a dog clutch or a collar, 0:15:07.720 --> 0:15:10.800 depending upon who you're talking to, and that is what 0:15:11.000 --> 0:15:14.520 is connected to a selector mechanism, which in the case 0:15:14.560 --> 0:15:16.680 of most vehicles, we think of as the stick shift, 0:15:16.680 --> 0:15:21.560 the manual shift. So, uh, the lay shaft is has 0:15:21.600 --> 0:15:25.560 got gears that are actually part of that shaft. They're 0:15:25.600 --> 0:15:29.760 they're they're splind spleened. Spleened is probably not the correct pronunciation, 0:15:29.760 --> 0:15:32.760 And I'm going to assume it's splend directly to the shaft. 0:15:32.960 --> 0:15:36.400 In other words, it's got a direct attachment. So as 0:15:36.520 --> 0:15:39.800 the chaft turns, so do the gears. Those gears have 0:15:40.000 --> 0:15:43.720 teeth along the edges and they interlocke with gears that 0:15:43.760 --> 0:15:45.800 are on the main shaft. But here's the big difference 0:15:45.840 --> 0:15:47.640 between the gears on the lay shaft and the ones 0:15:47.640 --> 0:15:49.960 on the main shaft. The gears on the main shaft 0:15:50.000 --> 0:15:53.480 are mounted on ball bearings, so they can spend freely 0:15:53.680 --> 0:15:57.080 around the axis of the main shaft without actually turning 0:15:57.240 --> 0:15:59.200 the main shift right, They're just kind of ghosting along 0:15:59.240 --> 0:16:01.920 over it into well, they become connected to the shaft 0:16:02.120 --> 0:16:04.680 through another piece of technology. Yeah, that would be the 0:16:04.720 --> 0:16:09.080 collar or dog clutch. Now, this is attached directly to 0:16:09.120 --> 0:16:11.240 the main shaft. It can slide to the left or 0:16:11.320 --> 0:16:14.680 right along the main shaft, but if it turns, the 0:16:14.720 --> 0:16:18.680 main shaft turns. So by interlocking the color with the 0:16:18.800 --> 0:16:21.880 side of one of these main shaft gears, both both 0:16:21.880 --> 0:16:24.920 the collar and the main shaft gears have teeth have 0:16:25.000 --> 0:16:29.120 teeth along the sides of them so that they can interlock. Yeah, exactly, So, 0:16:29.120 --> 0:16:31.320 so imagine that I think of it this way. You've 0:16:31.360 --> 0:16:34.240 got a gear that's got teeth along the outer edge 0:16:34.520 --> 0:16:36.840 like a like you would see in a typical gear, 0:16:37.200 --> 0:16:40.400 but you also have if you're looking at it from 0:16:40.440 --> 0:16:42.320 from one of the sides, so you're not looking at 0:16:42.320 --> 0:16:44.640 it headlong. You've turned it sideways, so you're looking at 0:16:44.680 --> 0:16:46.920 it like you know, like a plate you're holding it up, 0:16:47.320 --> 0:16:50.760 it would have teeth and holes along the surface that 0:16:50.760 --> 0:16:53.960 you're actually looking at, and those interlock with the collar 0:16:54.160 --> 0:16:56.800 or dog clutch, right, they kind of sandwich together. Right, 0:16:56.840 --> 0:16:59.800 So what happens is the lay shaft gears turn that 0:17:00.040 --> 0:17:02.360 makes the main shaft gears turn, and if the collar 0:17:02.720 --> 0:17:07.719 is is engaged in that particular mainshaft gear. Then the 0:17:07.760 --> 0:17:11.320 main shaft turns. Uh. I know, it sounds really confusing. 0:17:11.320 --> 0:17:14.840 It's a little difficult to get across without having visual effects. 0:17:14.840 --> 0:17:18.520 We will, by the way link on Facebook two pictures 0:17:18.520 --> 0:17:20.560 and videos of this, so it makes it easier to 0:17:20.560 --> 0:17:24.520 to to visualize and understand. But once you've got that 0:17:24.560 --> 0:17:28.439 main shaft turning, that's what then provides rotary motion to 0:17:28.480 --> 0:17:33.000 the differential. The differential's job is to to turn that 0:17:33.119 --> 0:17:36.480 rotary motion ninety degrees because at this point, before you 0:17:36.560 --> 0:17:40.880 hit the differential, that rotation is perpendicular to the wheels, 0:17:41.520 --> 0:17:43.879 which would not work. You wouldn't get the wheels to 0:17:43.920 --> 0:17:46.159 turn that way. Not very useful. Now, yeah, you have 0:17:46.200 --> 0:17:50.320 to turn that rotor rotation, that motion to be parallel 0:17:50.320 --> 0:17:51.840 with the wheels in order to get them to turn. 0:17:51.920 --> 0:17:54.160 So you can go forward or backward, depending upon which 0:17:54.200 --> 0:17:57.960 gear is is engaged. So the differential is a set 0:17:58.000 --> 0:18:01.080 of gears that transmits this dy degrees, so you can 0:18:01.119 --> 0:18:05.199 do that again. This is your basic five speed manual 0:18:05.240 --> 0:18:11.000 transmission with rear wheel drive. So that's the basic layout. 0:18:11.200 --> 0:18:14.240 But what's going on with the transmission alright? So remember 0:18:14.280 --> 0:18:16.280 I said that you had the lay shaft and the 0:18:16.280 --> 0:18:18.840 main shaft, both of which have gears on them. So 0:18:18.960 --> 0:18:22.720 imagine that the lay shaft gears are set up so 0:18:22.880 --> 0:18:26.320 it's gears that are increasing in size as you go 0:18:26.480 --> 0:18:30.000 from gear one to gear five, and then you have 0:18:30.600 --> 0:18:34.600 the your Your final gear on that shaft is for reverse. 0:18:34.640 --> 0:18:36.399 It's about the same size as the one that's going 0:18:36.440 --> 0:18:38.719 to be on the main shaft. Along the main shaft, 0:18:38.760 --> 0:18:41.359 of course, the gears are going to be in reverse 0:18:41.680 --> 0:18:44.840 order of size. So for the small lay shaft gear, 0:18:44.920 --> 0:18:48.040 you have a large main shaft gear, The next main 0:18:48.040 --> 0:18:50.240 shaft gear is a little smaller, the next one a 0:18:50.240 --> 0:18:52.920 little smaller, and a little smaller, so by the time 0:18:52.920 --> 0:18:55.320 you get to fifth gear, you've got a large lay 0:18:55.320 --> 0:18:59.720 shaft gear and a small main shaft gear. This is 0:18:59.720 --> 0:19:02.639 all because of that that relationship between speed and torque 0:19:02.680 --> 0:19:05.600 I was talking about. So if you've got a small 0:19:05.720 --> 0:19:09.080 lay shaft gear turning a large mainshaft gear, that means 0:19:09.119 --> 0:19:12.480 that the larger mainscheft gear has more torque but less speed. 0:19:13.000 --> 0:19:16.040 So that's important when you are accelerating from a stop 0:19:16.480 --> 0:19:18.879 so your car has not started moving, you want to 0:19:18.920 --> 0:19:22.080 engage that small gear on the lay shaft to turn 0:19:22.160 --> 0:19:24.760 the large gear on the main shaft so that you 0:19:24.800 --> 0:19:28.640 will start to accelerate from a stopped position. Now, once 0:19:28.680 --> 0:19:32.320 you start speeding up, you are eventually going to require 0:19:32.440 --> 0:19:34.760 the engine to do more power, more work than what 0:19:34.800 --> 0:19:36.919 it is comfortable doing. That's when you need to shift 0:19:37.040 --> 0:19:40.439 to second gear, which will be a decrease in torque 0:19:40.600 --> 0:19:43.600 but an increase in speed. And it's because that gear 0:19:43.720 --> 0:19:46.120 ratio has changed. The lay cheft gear is a little 0:19:46.160 --> 0:19:48.560 larger for gear too, and the main shift gears a 0:19:48.640 --> 0:19:51.280 little smaller for gear too. That's where you get that 0:19:51.400 --> 0:19:54.480 change in torque and speed. And this is true for 0:19:54.480 --> 0:19:57.960 for each speed step up, for each gear step up. Yeah, exactly. 0:19:58.000 --> 0:20:00.680 So once you get up to gear five, if that's 0:20:00.680 --> 0:20:04.360 when you're going really really fast, but I don't know, yeah, 0:20:04.359 --> 0:20:08.120 about as fast as the engine can hand without you know, 0:20:08.280 --> 0:20:12.160 having you drive off a cliff dukes of Hazzard style, 0:20:12.320 --> 0:20:14.879 in which case gravity takes control in your acceleration is 0:20:14.880 --> 0:20:20.160 completely dependent upon that. But that's the general progression. So 0:20:20.680 --> 0:20:23.480 if you're looking at how does the power flow, I'll 0:20:23.480 --> 0:20:25.760 walk you through it one more time. So power goes 0:20:25.800 --> 0:20:29.920 like this engine to pistons. Pistons to crankshaft, crank shaft 0:20:29.960 --> 0:20:33.479 to flywheel, flywheel to gear shaft, gear cheft to lay shaft, 0:20:33.760 --> 0:20:36.840 lay cheft to lay shaft gears, lay shaft gears to 0:20:36.960 --> 0:20:40.320 main shaft gears, mainshift gears to the dog clutch or 0:20:40.480 --> 0:20:45.080 color color to main shaft, main shaft to differential, differential 0:20:45.119 --> 0:20:47.640 to wheels and the wheels on the bus go round 0:20:47.680 --> 0:20:53.359 and round the red things connected to my wristwatch. Yeah, 0:20:53.520 --> 0:20:56.680 there you go. And so, uh, when when you are 0:20:56.720 --> 0:20:59.200 shifting gears, what what's actually happening is again you hit 0:20:59.200 --> 0:21:02.960 the clutch. It then separates the power of the engine 0:21:03.040 --> 0:21:07.359 from the from the gearbox down the line. So that 0:21:07.400 --> 0:21:10.960 allows you to move the collar or dog clutch from 0:21:11.000 --> 0:21:12.840 one of those gears to another. And if if you 0:21:12.880 --> 0:21:16.119 want to visualize it, imagine that you've got a horizontal 0:21:16.160 --> 0:21:20.159 pole and you've got gears going from the largest to 0:21:20.400 --> 0:21:22.720 the smallest and in reverse, which is kind of a 0:21:22.760 --> 0:21:24.640 medium sized gear. I'll get the reverse in a minute, 0:21:24.640 --> 0:21:26.359 because that one's kind of interesting, like how do you 0:21:26.400 --> 0:21:30.160 make it go backwards? You might say, well, um, you've 0:21:30.160 --> 0:21:34.359 got this this range of gears between each set of two, 0:21:34.800 --> 0:21:38.200 you've got one of those dog clutches or collars that's 0:21:38.320 --> 0:21:42.760 directly attached to the main shaft, all right, so that 0:21:42.760 --> 0:21:45.200 that collar can move to the left or right along 0:21:45.240 --> 0:21:48.439 this horizontal pole and engage either of the two gears 0:21:48.480 --> 0:21:50.480 that are on either side of it. And there, yeah, 0:21:50.520 --> 0:21:52.840 there's set of these in a in a manual five speed, 0:21:52.840 --> 0:21:55.560 there's going to be three of these collars, right because 0:21:55.640 --> 0:21:58.879 between gears one and two, gears three and four and 0:21:58.920 --> 0:22:02.920 gears five and verse, or you know, whatever configuration there are, 0:22:03.160 --> 0:22:05.760 that's that's where the collars would be and they would 0:22:05.840 --> 0:22:08.480 be able to engage either of the two whichever one 0:22:08.760 --> 0:22:12.200