WEBVTT - TechStuff Classic: TechStuff Shifts Into High Gear 0:00:04.400 --> 0:00:07.760 Welcome to text Stuff, a production from my Heart Radio. 0:00:11.840 --> 0:00:14.960 Hey there, and welcome to text Stuff. I'm your host, 0:00:15.200 --> 0:00:19.239 Jonathan Strickland. I'm an executive producer at I Heart Radio. 0:00:19.680 --> 0:00:22.840 And today it's time for another tech Stuff classic episode. 0:00:23.320 --> 0:00:28.280 This episode originally published way back on May six, two thirteen. 0:00:28.640 --> 0:00:32.440 It's called text Stuff Shifts into High Gear. And in 0:00:32.520 --> 0:00:35.440 this episode you can hear me and my former co host, 0:00:35.560 --> 0:00:40.240 Lauren Vogelbaum, who now hosts stuff like Savor and brain Stuff, 0:00:40.800 --> 0:00:46.320 as we try to explain how transmissions work. Let's a 0:00:46.440 --> 0:00:49.479 shift into it, shall we. So what are we talking 0:00:49.520 --> 0:00:53.360 about with transmissions? What are transmissions? Why are they necessary? 0:00:53.360 --> 0:00:57.200 What's the deal? Well, first, we have to understand that 0:00:57.960 --> 0:01:01.960 a vehicle, let's say a vehicle with an internal combustion engine, 0:01:02.640 --> 0:01:05.760 gets its power from the engine itself. Right, You're burning 0:01:05.800 --> 0:01:08.040 fuel within that engine, and that engine is putting out 0:01:08.040 --> 0:01:11.920 power in the form of kinetic energy. Now, the trick is, 0:01:12.200 --> 0:01:14.600 how do you make the kinetic energy that's generated by 0:01:14.600 --> 0:01:17.240 the engine make your vehicle move as opposed to just 0:01:17.360 --> 0:01:21.880 making noise or heat or explosions. That would be an 0:01:21.920 --> 0:01:25.199 external combustion engine not a good thing, not as useful 0:01:25.560 --> 0:01:30.120 emotion vehicles. Now, so, uh, what what's generally going on 0:01:30.319 --> 0:01:33.840 with a vehicle we're gonna take for this podcast. We're 0:01:33.840 --> 0:01:39.840 gonna specifically focus on a five speed manual transmission vehicle 0:01:40.000 --> 0:01:42.640 that has rear wheel drive. Now, there are a lot 0:01:42.680 --> 0:01:47.000 of different configurations you can have. The basic premise of 0:01:47.040 --> 0:01:49.040 the transmission is the same in all of these, but 0:01:49.120 --> 0:01:51.600 the way it's laid out is completely different depending upon 0:01:51.640 --> 0:01:54.800 the car's configuration. So this just for the purposes of 0:01:54.800 --> 0:01:57.080 this podcast, because we can't cover everything. It would be 0:01:57.160 --> 0:02:00.840 a four hour long pot least, and we we'd eventually 0:02:00.880 --> 0:02:03.840 say I don't even know where I am anymore. We're 0:02:03.840 --> 0:02:07.680 gonna keep it fairly simple. So, really, the transmission is 0:02:07.720 --> 0:02:11.359 important for being able to take the power that's an 0:02:11.400 --> 0:02:14.160 engine is generating and convert that into the kinetic energy 0:02:14.280 --> 0:02:17.440 that's necessary to get your vehicle moving. But before we 0:02:17.480 --> 0:02:21.000 get too far into that, let's kind of look back 0:02:21.200 --> 0:02:24.720 at why is a transmission even necessary? I mean, not 0:02:24.840 --> 0:02:27.360 beyond the fact of what it does. Why do we 0:02:27.400 --> 0:02:31.040 need something that like a variable transmission? Why not just 0:02:31.120 --> 0:02:34.200 something that converts the energy of an engine into the 0:02:34.720 --> 0:02:38.480 rotating force of wheels moving right? And this this has 0:02:38.480 --> 0:02:41.080 something to do with with the difference between, um, the 0:02:41.160 --> 0:02:43.079 kind of energy that you want to use when you're 0:02:43.240 --> 0:02:46.320 first starting a car, when you're accelerating it from a stop, 0:02:47.040 --> 0:02:50.800 and when you're speeding up later on down the line, right, 0:02:50.800 --> 0:02:54.240 and when you're when you're reaching your top speed as well. Yeah, 0:02:54.280 --> 0:02:56.840 as it turns out, an engine only has a very 0:02:56.919 --> 0:03:01.320 narrow range at which it's opera rating with its revolutions 0:03:01.320 --> 0:03:06.480 per minute, relatively narrow range. Uh. And if our vehicles 0:03:06.520 --> 0:03:10.000 worked within that same narrow range, we'd be fine, right, 0:03:10.040 --> 0:03:12.800 if everything was ideal, If somehow the range of the 0:03:12.840 --> 0:03:15.639 engine and the range of the motion of the wheels 0:03:15.840 --> 0:03:20.400 had a one to one ratio, whether it was directly uh, analogous, 0:03:20.520 --> 0:03:22.360 or you had to have some sort of gear shift 0:03:22.400 --> 0:03:25.800 in there too, uh to adjust it, we'd be all right. 0:03:25.840 --> 0:03:28.920 We wouldn't need a transmission, But we really need a 0:03:28.960 --> 0:03:32.920 wider range. And the two things that are really important 0:03:33.040 --> 0:03:36.280 when it comes to operating vehicles for for the purposes 0:03:36.280 --> 0:03:40.240 of this conversation, our speed and torque. Okay, so, so 0:03:40.280 --> 0:03:43.880 what's so? What's what? What is torque? Torque is is 0:03:44.680 --> 0:03:47.120 you can think of it as a twisting force. It's 0:03:47.160 --> 0:03:52.480 a rotational force. So whenever you have a wheel turning, uh, 0:03:52.680 --> 0:03:56.200 it's it's powered, it's that's that's that's torque there. Or 0:03:56.280 --> 0:03:58.560 if you're using a wrench, let's say that you need 0:03:58.640 --> 0:04:02.240 to loosen or tighten al with a wrench, you're using torque. 0:04:02.800 --> 0:04:05.440 It's this rotational force. The the end of the wrench 0:04:05.560 --> 0:04:08.480 is moving in a circle and the bolt is acting 0:04:08.520 --> 0:04:11.480 as sort of the axis of this of this pit 0:04:11.640 --> 0:04:15.080 or a pivot point for this motion. Uh. That's torque. 0:04:15.120 --> 0:04:19.040 And by increasing or decreasing torque, you can it's kind 0:04:19.080 --> 0:04:20.720 of what people talk about when they're talking about the 0:04:20.760 --> 0:04:24.400 grip on the road. Um, you can have a vehicle 0:04:24.480 --> 0:04:28.520 that has really high torque uh and really low speed. 0:04:28.640 --> 0:04:30.680 You can have a vehicle has really has speed really 0:04:30.720 --> 0:04:33.120 low torque. You can have lots of different combinations here. 0:04:33.160 --> 0:04:37.080 So for example, imagine a giant crane that you would 0:04:37.160 --> 0:04:40.480 use in a construction field. All right, so it's enormous 0:04:41.160 --> 0:04:44.360 and it's using wheels, not not treads or whatever. Uh, 0:04:44.520 --> 0:04:47.520 this vehicle is going to have an enormous amount of 0:04:47.560 --> 0:04:50.080 torque applied to the wheels in order to move this 0:04:50.320 --> 0:04:53.479 massive vehicle around. It may not be moving quickly but 0:04:53.520 --> 0:04:56.120 the torque is really powerful, which means that it would 0:04:56.200 --> 0:04:59.480 require a lot of force to make sure that those 0:04:59.480 --> 0:05:03.200 wheels don't turn. If the engine were operational and it 0:05:03.279 --> 0:05:05.440 was being put into drive, if you were trying to 0:05:05.480 --> 0:05:07.599 hold those wheels still, you would have to use an 0:05:07.720 --> 0:05:11.120 enormous amount of force to counteract that torque. You could 0:05:11.160 --> 0:05:14.320 also have a toy, let's say that has a little 0:05:14.320 --> 0:05:18.039 spinning element to it that spins at an incredible rpm, 0:05:18.040 --> 0:05:21.000 but it doesn't do so very with very much torque 0:05:21.040 --> 0:05:22.920 at all. So if you just touched it, it would 0:05:22.960 --> 0:05:25.880 stop spinning, and it would just be the lightest touch 0:05:25.960 --> 0:05:28.839 to counteract that torque. Again, the torque is not very 0:05:28.920 --> 0:05:33.800 strong with that particular device. So when we're operating our vehicles, 0:05:33.960 --> 0:05:37.680 we actually need a fairly wide range of torque, which 0:05:37.800 --> 0:05:40.480 is not something that would be possible if we had 0:05:40.520 --> 0:05:43.200 to work within the narrow parameters of what an engine 0:05:43.279 --> 0:05:45.600 is able to put out with that range of RPMs. Right, 0:05:45.640 --> 0:05:48.840 if an engine only had one speed, it would get 0:05:48.839 --> 0:05:52.120 really messy, really fast, right and exactly, And you know, 0:05:52.160 --> 0:05:55.840 the vehicle might operate fine in certain conditions, but if 0:05:55.880 --> 0:05:58.960 you change those conditions at all, then you'd be in trouble. 0:05:59.040 --> 0:06:02.160 And see that's the the issue, right because we all 0:06:02.200 --> 0:06:04.719 know when you're out there driving, not everything is a 0:06:04.760 --> 0:06:08.080 perfectly flat highway. You know you're going to have inclines, 0:06:08.080 --> 0:06:11.400 you're gonna have changes in the in the environmental conditions 0:06:11.400 --> 0:06:14.479 that are going to require your vehicle to adjust as 0:06:14.520 --> 0:06:16.600 you are going through them. So that's why you need 0:06:16.640 --> 0:06:18.960 to have a transmission. You have to have something where 0:06:19.040 --> 0:06:23.160 you can shift to a different torque or speed in 0:06:23.240 --> 0:06:26.320 order to one maintain your grip on the road and 0:06:26.360 --> 0:06:30.479 continue moving at the appropriate speed and to operate within 0:06:30.640 --> 0:06:33.880 the engine's parameters. That's one of those reasons why, Like 0:06:33.920 --> 0:06:36.160 if you keep revving the engine and you're in first gear, 0:06:36.440 --> 0:06:38.159 you'll see that needle go all the way into the 0:06:38.200 --> 0:06:40.320 red and then if you keep that up, you burn 0:06:40.360 --> 0:06:43.760 out your engine. So by shifting, you are actually adjusting 0:06:43.880 --> 0:06:47.480 torque and speed and by doing that you can keep 0:06:47.560 --> 0:06:52.960 the needle in the the ideal operational So that's what 0:06:53.040 --> 0:06:55.599 the transmission is for. It's for keeping you in this 0:06:56.200 --> 0:07:00.560 in the sweet spot. And there are of course manual transmissions, 0:07:00.640 --> 0:07:05.400 automatic transmissions, there are variants of those UM and UH. 0:07:05.440 --> 0:07:08.280 And while we're really focusing on manual transmissions. If we 0:07:08.279 --> 0:07:11.040 were to talk about automatic I think I would have 0:07:11.160 --> 0:07:14.800 to call someone else in because we would need scotten here, 0:07:14.840 --> 0:07:17.760 because it's a little bit beyond what we are certainly 0:07:17.800 --> 0:07:21.200 our personal technical level with the automotive industry. Not to 0:07:21.240 --> 0:07:23.239 mention the fact that I don't know how I would 0:07:23.360 --> 0:07:26.400 explain it in words without the benefit of pictures. It's 0:07:26.440 --> 0:07:29.040 already given me an interpretive dance, and that works less 0:07:29.040 --> 0:07:32.040 well on podcasts. You might you might hear us like 0:07:32.240 --> 0:07:35.080 with by the microphone, but it kind of loses something 0:07:35.120 --> 0:07:38.960 in the translation. Right. But so, originally automobiles only had 0:07:39.240 --> 0:07:43.040 two forward gears in one reverse. So, but they're the 0:07:43.120 --> 0:07:46.400 engine capacity was much less so so those narrow ranges 0:07:46.480 --> 0:07:50.200 were kind of okay within two gears. UM. Around the 0:07:50.640 --> 0:07:54.760 early nineteen forties late nineteen thirties, um Ford and Chrysler 0:07:54.800 --> 0:07:58.840 started introducing semi automatic gears that would let you UM. 0:07:59.120 --> 0:08:01.240 You still had to use a clutch, but you could, 0:08:01.280 --> 0:08:04.440 but you could switch between them between the higher gear 0:08:04.520 --> 0:08:08.520 semi automatically. UM. In the nineteen fifties, the first full 0:08:08.560 --> 0:08:11.480 automatics were debuted and UH and then after that all 0:08:11.520 --> 0:08:13.960 of the advances have been in the in the number 0:08:14.000 --> 0:08:16.360 of speeds, the number of gears that are involved in 0:08:16.360 --> 0:08:19.280 these transmissions. So we went from we went from two 0:08:19.360 --> 0:08:22.280 up to uh four speed manuals, and then six speed 0:08:22.280 --> 0:08:26.960 manuals started hitting the market in the late nineteen eighties, right, So, uh, 0:08:27.000 --> 0:08:29.680 and you I wonder why do you have why why 0:08:29.680 --> 0:08:32.920 do you add more of those divisions, more of those speeds. 0:08:33.080 --> 0:08:35.440 It doesn't necessarily mean that the vehicle is going to 0:08:35.480 --> 0:08:38.560 go faster than earlier vehicles. It does mean that the 0:08:38.600 --> 0:08:42.400 transitions between between the different speeds or the different gears 0:08:42.760 --> 0:08:46.360 becomes a little more smooth because you've you've refined them, 0:08:46.400 --> 0:08:48.360 You've you've made it a little more precise, all right. 0:08:48.360 --> 0:08:52.040 It lets the engines work less hard at the specific 0:08:52.040 --> 0:08:53.920 task that you were asking them to do at the time. 0:08:54.440 --> 0:08:57.880 Along these lines, just just about a couple of days ago, 0:08:58.040 --> 0:09:01.800 as of the recording of this podcast, admit a GM 0:09:01.840 --> 0:09:04.360 and four general motors of course, and Ford announced that 0:09:04.400 --> 0:09:06.920 they're going to to work together to develop nine and 0:09:07.000 --> 0:09:11.400 ten speed transmissions. I'm assuming those are automatic transmissions at 0:09:11.400 --> 0:09:13.640 this point, because that sounds like a very large gearshift 0:09:15.240 --> 0:09:17.560 that will you know, for for consumer vehicles, and that 0:09:17.600 --> 0:09:20.719 will uh, you know, save gas mileage. It could it 0:09:20.760 --> 0:09:23.240 could raise gas mileage by five to ten percent, which is, 0:09:23.400 --> 0:09:26.240 you know, not not insignificant, right, and then you're talking 0:09:26.280 --> 0:09:29.040 about decreased environmental impact. There are a lot of other 0:09:29.080 --> 0:09:32.840 benefits that roll out through these, uh some people might 0:09:32.840 --> 0:09:36.000 call them small evolutionary changes, but they can make a 0:09:36.040 --> 0:09:39.400 big difference down the road. Did not mean to do 0:09:39.440 --> 0:09:43.560 a pun there on the accidental puns. We don't. We 0:09:43.600 --> 0:09:45.560 don't need any of those mean to do it, all right, 0:09:45.679 --> 0:09:48.080 So so you might be thinking, all right, how does 0:09:48.080 --> 0:09:51.719 this whole torque shifting thing work? And we're going to 0:09:51.800 --> 0:09:55.680 get into the actual mechanics literally of it in a 0:09:55.720 --> 0:10:00.200 little bit, but in general, think of two gears. Right, 0:10:00.240 --> 0:10:02.600 If you have two gears of the same size and 0:10:02.640 --> 0:10:06.000 they are they have teeth that interlock. When you turn 0:10:06.080 --> 0:10:08.480 one gear, the other gear is going to turn at 0:10:08.520 --> 0:10:10.240 that same rate. It's going to be the same number 0:10:10.280 --> 0:10:12.480 of revolutions per minute because they are the same size, 0:10:12.520 --> 0:10:15.640 same same number of teeth, all that kind of stuff. Now, 0:10:15.720 --> 0:10:18.959 let's say that you have a large gear and a 0:10:19.160 --> 0:10:22.680 smaller gear and they are interlocking, and you're turning the 0:10:22.800 --> 0:10:25.160 large gear, that smaller gear is going to do more 0:10:25.200 --> 0:10:28.600 revolutions per minute than the large gear. You know, when 0:10:28.640 --> 0:10:31.120 you go from the starting point all the way back 0:10:31.160 --> 0:10:33.240 around to the starting point in the large gear, the 0:10:33.280 --> 0:10:35.720 small one may have turned three or four times, depending 0:10:35.760 --> 0:10:39.160 upon the ratio between the two. Right, same thing, If 0:10:39.200 --> 0:10:41.440 you have a small gear and a large gear and 0:10:41.440 --> 0:10:43.400 you're turning the small gear, you're gonna have to turn 0:10:43.440 --> 0:10:48.360 that small gear several times large gear to right exactly. 0:10:48.400 --> 0:10:51.640 And and these these differences in speed also result in 0:10:51.679 --> 0:10:55.040 a difference in torque. So that's what's going to become 0:10:55.080 --> 0:10:58.560 important when we start talking about the actual process of 0:10:58.679 --> 0:11:02.440 shifting and what is going on with the transmission. For 0:11:02.520 --> 0:11:04.240 us to understand that, we're really gonna have to take 0:11:04.280 --> 0:11:07.439 a look at the entire drive train of a vehicle, 0:11:07.760 --> 0:11:12.680 which is both exciting and intimidating to me. I think, so, 0:11:12.760 --> 0:11:14.599 I think it's really cool. It's this is this is 0:11:14.640 --> 0:11:17.480 really entertaining physics to me because I have I have, 0:11:17.640 --> 0:11:21.400 I mean, Jonathan doesn't really drive. No, Jonathan doesn't drive. 0:11:21.640 --> 0:11:23.920 Don't don't even bother putting the word really in there. 0:11:24.000 --> 0:11:28.520 Jonathan does not drive. We we fortunately have a limitedly 0:11:28.720 --> 0:11:33.080 robust public transports. I can Atlanta, I can get generally 0:11:33.160 --> 0:11:35.920 to where I need to go. Um uh, and I 0:11:36.360 --> 0:11:38.480 do drive, but I'm a very I'm not I'm not 0:11:38.480 --> 0:11:40.960 particularly a car person, so but this isn't so this 0:11:41.040 --> 0:11:43.360 is going to be an exciting Yes. I will ask 0:11:43.440 --> 0:11:47.320 Lauren about her experiences with manual transmissions later on in 0:11:47.320 --> 0:11:50.240 the podcast, so stay tuned to find out about Lauren's 0:11:50.280 --> 0:11:54.480 own personal adventures with this technology. Guys, we're gonna pop 0:11:54.600 --> 0:11:57.680 this podcast into neutral for a second so that we 0:11:57.720 --> 0:12:07.800 can take a break to thank our sponsors. All right, 0:12:07.880 --> 0:12:11.600 let's get back to how transmissions actually work. So to 0:12:11.640 --> 0:12:15.120 do this, we have to look at the entire system 0:12:15.200 --> 0:12:18.280 that makes the car go. All right, and you're you're 0:12:18.320 --> 0:12:21.280 only interacting in this five speed manual transmission that we 0:12:21.280 --> 0:12:23.800 were talking about with with two bits about the clutch 0:12:23.880 --> 0:12:26.520 and the gearshift. Yeah yeah, but but there's a lot 0:12:26.559 --> 0:12:30.160 going on under this, Yes, a whole lot. And so 0:12:30.320 --> 0:12:32.600 first we need to just understand what these what these 0:12:32.720 --> 0:12:36.800 different parts are. So you've got your car's engine, this 0:12:36.920 --> 0:12:40.720 is the thing that makes it go. Ultimately, as you 0:12:40.840 --> 0:12:44.120 are depressing the gas pedal, you are putting in more 0:12:44.160 --> 0:12:47.600 fuel to the engine, which is then generating more uh power. 0:12:47.720 --> 0:12:50.120 It creates more kinetic energy in the form of the 0:12:50.120 --> 0:12:54.120 pistons moving up and down. Those pistons are connected to 0:12:54.400 --> 0:12:59.160 a crank shaft, which converts the reciprocating motion that's the 0:12:59.280 --> 0:13:02.760 up and down motion of the pistons, into rotary motion, 0:13:02.840 --> 0:13:06.800 meaning it's turning into turning in a circular pattern. Now, 0:13:06.880 --> 0:13:10.280 so the crank shaft goes from the up down motion 0:13:10.320 --> 0:13:13.040 to the rotation motion, which is the very basis of 0:13:13.280 --> 0:13:17.520 everything else that's going to happen. Now, the crank shaft 0:13:17.880 --> 0:13:22.440 connects to a flywheel. Now, the fly wheel transmits this 0:13:22.559 --> 0:13:26.400 rotary rotary motion to a clutch plate, and the clutch 0:13:26.440 --> 0:13:30.000 plate is what eventually connects to that clutch pedal. Yeah. Yeah, 0:13:30.080 --> 0:13:32.800 In fact, there's a pressure plate that is pressed up 0:13:32.840 --> 0:13:35.520 against the clutch plate, right. So the pressure plate, when 0:13:35.520 --> 0:13:39.240 it's in contact with the clutch plate, allows this rotary 0:13:39.320 --> 0:13:42.360 motion to transmit through the rest of the of the 0:13:42.480 --> 0:13:45.720 vehicle's drive strain. So when these two things are in 0:13:45.800 --> 0:13:49.360 contact with one another, uh, as long as the engine 0:13:49.360 --> 0:13:53.120 is going, then there is some sort of rotation being 0:13:53.880 --> 0:13:57.520 transmitted at that point, assuming you're not in just a 0:13:57.559 --> 0:14:00.679 neutral So what happens when you hit the clutch, Well, 0:14:00.679 --> 0:14:04.480 When you hit the clutch, the pressure plate rises up 0:14:04.520 --> 0:14:08.400 off of lifts off the clutch plate. Once the pressure 0:14:08.400 --> 0:14:12.400 plates separates from the clutch plate, all power is cut 0:14:12.440 --> 0:14:14.760 off to the list of the transmission, the rest of 0:14:14.760 --> 0:14:19.040 the transmission exactly. So so while the engine is still going, uh, 0:14:19.040 --> 0:14:24.080 it is not providing rotary force to the transmission and wheels, 0:14:24.160 --> 0:14:26.960 which is what allows you to shift gears exactly without 0:14:27.200 --> 0:14:29.600 making things explode. All right, this is why you why 0:14:29.680 --> 0:14:32.760 if you're driving a manual, you know, you're driving stick, 0:14:33.080 --> 0:14:35.680 you have to hit the clutch first, because that ends 0:14:35.720 --> 0:14:37.600 up pulling that pressure plate off so that you are 0:14:37.840 --> 0:14:41.400 able to shift gears without making the horrible grinding noise 0:14:41.720 --> 0:14:45.760 and destroying your big brother's vehicle. Uh. I say big 0:14:45.840 --> 0:14:49.920 brother because I know a guy who did do that. Yeah, yeah, 0:14:49.960 --> 0:14:53.400 I was not there, thankfully. So, assuming that the clutch 0:14:53.440 --> 0:14:55.720 plate and pressure plate are in contact with one another, 0:14:55.800 --> 0:14:58.720 you you have not just hit the clutch um it 0:14:58.800 --> 0:15:04.600 has been providing the a rotary motion to the gearbox shaft. Now, 0:15:04.600 --> 0:15:08.480 the gearbox consists of several parts itself. You've got the 0:15:09.880 --> 0:15:12.200 main well, You've got a lay shaft which is connected 0:15:12.200 --> 0:15:15.760 to that gearbox shaft. You've got a main shaft and 0:15:15.800 --> 0:15:19.480 you've got several gears attached to both. You also have 0:15:19.600 --> 0:15:22.520 something that's either called a dog clutch or a collar, 0:15:22.680 --> 0:15:25.720 depending upon who you're talking to, and that is what 0:15:25.960 --> 0:15:29.480 is connected to a selector mechanism, which in the case 0:15:29.520 --> 0:15:31.600 of most vehicles, we think of as the stick shaft 0:15:31.640 --> 0:15:36.520 the manual shift. So, uh, the lay shaft is has 0:15:36.560 --> 0:15:40.520 got gears that are actually part of that shaft. They're 0:15:40.560 --> 0:15:44.720 they're they're spline spleened. Spleened is probably not the correct pronunciation. 0:15:44.800 --> 0:15:47.720 I'm going to a sayment's splind directly to the cheft. 0:15:47.920 --> 0:15:51.400 In other words, it's got a direct attachment. So as 0:15:51.440 --> 0:15:54.760 the chaft turns, so do the gears. Those gears have 0:15:54.920 --> 0:15:58.680 teeth along the edges and they interlocke with gears that 0:15:58.720 --> 0:16:00.760 are on the main shaft. But here's the big difference 0:16:00.800 --> 0:16:02.600 between the gears on the lay shaft and the ones 0:16:02.600 --> 0:16:04.920 on the main shaft. The gears on the main shaft 0:16:04.960 --> 0:16:08.440 are mounted on ball bearings, so they can spend freely 0:16:08.640 --> 0:16:12.040 around the axis of the main shaft without actually turning 0:16:12.160 --> 0:16:14.160 the main shift right. They're just kind of ghosting along 0:16:14.200 --> 0:16:17.320 over it until they become connected to the shaft through 0:16:17.520 --> 0:16:20.040 another piece of technology. Yeah, that would be the collar 0:16:20.200 --> 0:16:24.160 or dog clutch. Now, this is attached directly to the 0:16:24.160 --> 0:16:26.520 main shaft. It can slide to the left or right 0:16:26.640 --> 0:16:29.880 along the main shaft, but if it turns, the main 0:16:29.960 --> 0:16:34.120 shaft turns. So by interlocking the collar with the side 0:16:34.240 --> 0:16:36.960 of one of these main shaft gears, both both the 0:16:36.960 --> 0:16:40.240 collar and the main shaft gears have teeth have teeth 0:16:40.280 --> 0:16:44.080 along the sides of them so that they can interlock. Yeah, exactly. So, 0:16:44.080 --> 0:16:46.280 so imagine that I think of it this way. You've 0:16:46.280 --> 0:16:49.160 got a gear that's got teeth along the outer edge, 0:16:49.480 --> 0:16:51.800 like a like you would see in a typical gear, 0:16:52.120 --> 0:16:55.240 but you also have if you're looking at it from 0:16:55.400 --> 0:16:57.280 from one of the sides, so you're not looking at 0:16:57.280 --> 0:16:59.600 it headlong. You've turned it sideways, so you're looking at 0:16:59.600 --> 0:17:02.320 it like like a plate you're holding it up, it 0:17:02.360 --> 0:17:05.880 would have teeth and holes along the surface that you're 0:17:05.880 --> 0:17:09.159 actually looking at, and those interlock with the collar or 0:17:09.240 --> 0:17:11.919 dog clutch. Right, they kind of sandwich together. Right, So 0:17:11.960 --> 0:17:15.160 what happens is the lay shaft gears turn. That makes 0:17:15.200 --> 0:17:18.440 the main shaft gears turn, and if the collar is 0:17:18.440 --> 0:17:22.639 is engaged in that particular main shaft gear. Then the 0:17:22.680 --> 0:17:26.399 main shaft turns. I know, it sounds really confusing. It's 0:17:26.400 --> 0:17:29.800 a little difficult to get across without having visual effects. 0:17:29.800 --> 0:17:33.480 We will, by the way link on Facebook two pictures 0:17:33.480 --> 0:17:35.520 and videos of this, so it makes it easier to 0:17:35.520 --> 0:17:39.480 to to visualize and understand. But once you've got that 0:17:39.520 --> 0:17:43.399 main shaft turning, that's what then provides rotary motion to 0:17:43.440 --> 0:17:47.960 the differential. The differentials job is to to turn that 0:17:48.080 --> 0:17:51.439 rotary emotion ninety degrees because at this point, before you 0:17:51.480 --> 0:17:55.840 hit the differential, that rotation is perpendicular to the wheels, 0:17:56.440 --> 0:17:58.840 which would not work. You wouldn't get the wheels to 0:17:58.880 --> 0:18:01.119 turn that way. Not very useful. Now, yeah, you have 0:18:01.160 --> 0:18:05.240 to turn that rot rotation, that motion to be parallel 0:18:05.280 --> 0:18:06.800 with the wheels in order to get them to turn. 0:18:06.880 --> 0:18:09.120 So you can go forward or backward, depending upon which 0:18:09.160 --> 0:18:12.920 gear is is engaged. So the differential is a set 0:18:12.960 --> 0:18:16.040 of gears that transmits this ninety degrees, so you can 0:18:16.080 --> 0:18:20.159 do that again. This is your basic five speed manual 0:18:20.200 --> 0:18:25.960 transmission with rear wheel drive. So that's the basic layout. 0:18:26.119 --> 0:18:29.199 But what's going on with the transmission alright? So remember 0:18:29.240 --> 0:18:31.199 I said that you had the lay shaft and the 0:18:31.240 --> 0:18:33.800 main shaft, both of which have gears on them. So 0:18:33.920 --> 0:18:37.680 imagine that the lay shaft gears are set up so 0:18:37.840 --> 0:18:41.280 it's gears that are increasing in size as you go 0:18:41.400 --> 0:18:44.960 from gear one to gear five, and then you have 0:18:45.800 --> 0:18:49.560 your Your final gear on that shaft is for reverse. 0:18:49.600 --> 0:18:51.359 It's about the same size as the one that's going 0:18:51.400 --> 0:18:54.000 to be on the main shaft. Along the main shaft, 0:18:54.040 --> 0:18:56.639 of course, the gears are going to be in reverse 0:18:56.960 --> 0:19:00.200 order of size. So for the small lay shaft gear, 0:19:00.240 --> 0:19:03.320 you have a large main shaft gear, The next main 0:19:03.359 --> 0:19:05.520 shaft gear is a little smaller, the next one a 0:19:05.520 --> 0:19:08.200 little smaller, and a little smaller, so by the time 0:19:08.240 --> 0:19:10.600 you get to fifth gear, you've got a large lay 0:19:10.640 --> 0:19:15.000 shaft gear and a small main shaft gear. This is 0:19:15.040 --> 0:19:17.920 all because of that that relationship between speed and torque 0:19:17.960 --> 0:19:20.879 I was talking about. So if you've got a small 0:19:21.000 --> 0:19:24.080 lay shaft gear turning a large main shaft gear, that 0:19:24.160 --> 0:19:26.760 means that the larger main shaft gear has more torque 0:19:26.840 --> 0:19:30.640 but less speed. So that's important when you are accelerating 0:19:30.680 --> 0:19:33.520 from a stop so your car has not started moving, 0:19:33.760 --> 0:19:36.239 you want to engage that small gear on the lay 0:19:36.320 --> 0:19:39.240 shaft to turn the large gear on the main shaft 0:19:39.520 --> 0:19:43.639 so that you will start to accelerate from a stopped position. Now, 0:19:43.760 --> 0:19:46.359 once you start speeding up, you are eventually going to 0:19:47.080 --> 0:19:49.880 require the engine to do more power, more work than 0:19:49.920 --> 0:19:51.840 what it is comfortable doing. That's when you need to 0:19:51.880 --> 0:19:55.320 shift to second gear, which will be a decrease in 0:19:55.359 --> 0:19:58.560 torque but an increase in speed. And it's because that 0:19:58.640 --> 0:20:01.159 gear ratio has changed. The lay shaft gear is a 0:20:01.160 --> 0:20:03.800 little larger for gear too, and the main shaft gears 0:20:03.840 --> 0:20:06.400 a little smaller for gear too. That's where you get 0:20:06.440 --> 0:20:09.440 that change in torque and speed. And this is true 0:20:09.480 --> 0:20:13.240 for for each speed step up, for each gear step up. Yeah, exactly. 0:20:13.280 --> 0:20:16.120 So once you get up to gear five, that's when 0:20:16.119 --> 0:20:19.680 you're going really really fast, but I don't know, yeah, 0:20:19.680 --> 0:20:21.800 about as fast as the engine can can hand out 0:20:22.680 --> 0:20:26.639 without you know, having you drive off a cliff dukes 0:20:26.640 --> 0:20:29.320 of Hazzard style, in which case gravity takes control in 0:20:29.359 --> 0:20:33.040 your acceleration is completely dependent upon that. But that's the 0:20:33.080 --> 0:20:37.200 general progression we're getting towards the end. But before we 0:20:37.240 --> 0:20:40.840 actually do shift into high gear, let's take another quick break. 0:20:49.560 --> 0:20:52.679 So if you're looking at how does the power flow 0:20:52.920 --> 0:20:55.200 I'll walk you through it one more time. So power 0:20:55.240 --> 0:20:59.280 goes like this engine to pistons, pistons to crankshaft, crank 0:20:59.320 --> 0:21:01.560 shaft to fly with will fly wheel to gear shaft, 0:21:01.840 --> 0:21:05.120 gear cheft to lay shaft, lay cheft to lay shaft gears, 0:21:05.560 --> 0:21:08.800 lay shaft gears to main shaft gears, main shift gears 0:21:08.840 --> 0:21:12.160 to the dog clutch or collar color to main shaft, 0:21:12.520 --> 0:21:16.480 main cheft to differential, differential to wheels, and the wheels 0:21:16.480 --> 0:21:20.920 on the bus go round and round. Alternately, the red 0:21:21.000 --> 0:21:25.399 things connected to my wristwatch. Yeah, there you go. And so, uh, 0:21:25.600 --> 0:21:28.159 when when you are shifting gears, what's actually happening is 0:21:28.200 --> 0:21:31.479 again you hit the clutch. It then separates the power 0:21:31.720 --> 0:21:36.119 of the engine from the from the gearbox down the line. 0:21:36.600 --> 0:21:39.520 So that allows you to move the collar or dog 0:21:39.560 --> 0:21:42.159 clutch from one of those gears to another. And if 0:21:42.160 --> 0:21:44.160 you if you want to visualize and imagine that you've 0:21:44.160 --> 0:21:49.080 got a horizontal pole and you've got gears going from 0:21:49.119 --> 0:21:51.960 the largest to the smallest end in reverse, which is 0:21:52.040 --> 0:21:53.920 kind of a medium sized gear. I'll get the reverse 0:21:53.960 --> 0:21:55.520 in a minute, because that one's kind of interesting, like 0:21:55.560 --> 0:21:59.439 how do you make it go backwards? You might say, well, um, 0:21:59.560 --> 0:22:03.119 you've got uh, this this range of gears. Between each 0:22:03.240 --> 0:22:06.440 set of two, you've got one of those dog clutches 0:22:06.520 --> 0:22:10.560 or collars that's directly attached to the main shaft, all right, 0:22:11.119 --> 0:22:14.240 so that that collar can move to the left or 0:22:14.320 --> 0:22:17.320 right along this horizontal pole and engage either of the 0:22:17.440 --> 0:22:20.120 two gears that are on either side of it. And there, yeah, 0:22:20.160 --> 0:22:22.440 there's set of these in a in a manual five speed, 0:22:22.480 --> 0:22:25.200 there's going to be three of these collars, right because 0:22:25.280 --> 0:22:28.480 between gears one and two, gears three and four, and 0:22:28.560 --> 0:22:32.440 gears five and reverse, or you know, whatever configuration there are, 0:22:32.800 --> 0:22:35.400