WEBVTT - TechStuff Shifts Into High Gear 0:00:03.960 --> 0:00:07.000 Get in touch with technology with tex Stuff from how 0:00:07.040 --> 0:00:16.720 stuff dot com. Every Hey there, everyone a d Welcome 0:00:16.800 --> 0:00:20.720 to tech Stuff. I'm Jonathan Strickland, and and today we 0:00:20.760 --> 0:00:24.160 wanted to talk about Well, let's let one of our 0:00:24.200 --> 0:00:27.280 listeners decide what we're gonna talk about. This comes from 0:00:27.440 --> 0:00:29.840 Eric via Twitter, and he says, have you guys ever 0:00:29.880 --> 0:00:32.720 done an episode in transmissions? I think it'd be interesting. 0:00:33.320 --> 0:00:35.800 The answer to that is no, we are assuming of 0:00:35.840 --> 0:00:40.560 course he's talking about automotive transmissions. Yes, because he could 0:00:40.640 --> 0:00:44.120 be talking about radio transmissions, in which case we already 0:00:44.159 --> 0:00:45.960 did a podcast on that, but we haven't done one 0:00:45.960 --> 0:00:48.760 on automotive ones, right, because usually we don't actually do 0:00:48.920 --> 0:00:52.320 stuff about automotive technology, because we have a whole separate 0:00:52.320 --> 0:00:55.480 show about that. Yeah, car stuff. Scott and Ben they 0:00:55.640 --> 0:01:00.360 covered actually, let's be fair, Scott covers it, Ben asks questions, Uh, 0:01:00.360 --> 0:01:02.760 and we wouldn't have it any other way. Scott is brilliant, 0:01:02.800 --> 0:01:05.600 Scott Benjamin, he's ourn auto editor here at how Stuff Works, 0:01:05.680 --> 0:01:08.840 and he he's one of those quietly brilliant people who's 0:01:08.920 --> 0:01:13.039 just who's just silent until he just absolutely blazes you 0:01:13.120 --> 0:01:15.839 with something ridiculously intelligent. Yeah, you asked him a question, 0:01:15.920 --> 0:01:19.240 and you're you're still wanted to run deep man? Uh? Yeah, 0:01:19.240 --> 0:01:21.360 he's a he's a he's a force to be reckoned with. 0:01:21.640 --> 0:01:23.800 And we actually checked with them first to see if 0:01:23.840 --> 0:01:27.039 they had done an episode on transmissions, and according to Ben, 0:01:27.160 --> 0:01:30.160 they have not, so we thought, well, heck, we'll tackle 0:01:30.280 --> 0:01:32.760 this one and uh and then maybe Car Stuff will 0:01:32.840 --> 0:01:35.919 will school us later on down the line. But and guys, 0:01:35.920 --> 0:01:38.800 if you have not listened to Car Stuff, go check 0:01:38.800 --> 0:01:41.920 it out. It's it's really for everyone, from someone who 0:01:42.040 --> 0:01:46.080 is a real automotive enthusiast to a newbie who finds 0:01:46.120 --> 0:01:50.000 these card terms to be really really difficult to grasp, 0:01:50.120 --> 0:01:52.040 like me. I mean, I am not a car guy, 0:01:52.440 --> 0:01:55.240 so I really enjoyed them. But I know that people 0:01:55.280 --> 0:01:57.240 who are gear heads, who you know, like to get 0:01:57.280 --> 0:01:59.640 in there and really work on vehicles themselves, they love 0:01:59.640 --> 0:02:02.680 it too. So if you're technical but also extremely clear, 0:02:02.880 --> 0:02:05.040 yeah yeah, so definitely check that out. And and Ben 0:02:05.160 --> 0:02:07.240 kind of acts acts as the voice for the person 0:02:07.280 --> 0:02:09.280 who has no idea what's going on, because that's who 0:02:09.320 --> 0:02:13.440 been is. So let's talk about I mean, he'll be 0:02:13.480 --> 0:02:15.680 the first to admit that. So what are we talking 0:02:15.760 --> 0:02:19.560 about with transmissions. What are transmissions? Why are they necessary? 0:02:19.600 --> 0:02:23.480 What's the deal? Well, first, we have to understand that 0:02:24.200 --> 0:02:28.200 a vehicle, let's say a vehicle with an internal combustion engine, 0:02:28.880 --> 0:02:32.000 gets its power from the engine itself. Right, You're burning 0:02:32.040 --> 0:02:34.280 fuel within that engine, and that engine is putting out 0:02:34.280 --> 0:02:38.200 power in the form of kinetic energy. Now, the trick is, 0:02:38.440 --> 0:02:40.800 how do you make the kinetic energy that's generated by 0:02:40.840 --> 0:02:43.480 the engine make your vehicle move as opposed to just 0:02:43.600 --> 0:02:48.160 making noise or heat or explosions. That would be an 0:02:48.160 --> 0:02:54.440 external combustion engine not a good thing vehicles. Now, So, uh, 0:02:54.919 --> 0:02:58.840 what what's generally going on with a vehicle we're gonna 0:02:58.880 --> 0:03:02.320 take for this podcast. We're gonna specifically focus on a 0:03:02.680 --> 0:03:08.440 five speed manual transmission vehicle that has rear wheel drive. Now, 0:03:08.440 --> 0:03:10.520 there are a lot of different configurations you can have. 0:03:11.280 --> 0:03:14.679 The basic premise of the transmission is the same in 0:03:14.720 --> 0:03:16.480 all of these, but the way it's laid out is 0:03:16.520 --> 0:03:20.240 completely different depending upon the car's configuration. So this just 0:03:20.320 --> 0:03:22.840 for the purposes of this podcast, because we can't cover everything. 0:03:22.840 --> 0:03:25.680 It would be a four hour long pod least, and 0:03:25.840 --> 0:03:28.760 we we we'd eventually say, I don't even know where 0:03:28.800 --> 0:03:32.320 I am anymore, we're gonna keep it fairly simple. So, really, 0:03:32.800 --> 0:03:36.720 the transmission is important for being able to take the 0:03:36.760 --> 0:03:39.440 power that an engine is generating and convert that into 0:03:39.480 --> 0:03:42.760 the kinetic energy that's necessary to get your vehicle moving. 0:03:43.120 --> 0:03:46.200 But before we get too far into that, let's kind 0:03:46.200 --> 0:03:50.520 of look back at why is a transmission even necessary? 0:03:50.600 --> 0:03:52.640 I mean, not beyond the fact that what it does. 0:03:53.120 --> 0:03:56.640 Why do we need something that like a variable transmission? 0:03:56.840 --> 0:03:59.360 Why not just something that converts the energy of an 0:03:59.360 --> 0:04:03.480 engine into to the rotating force of wheels moving right. 0:04:03.560 --> 0:04:05.760 And this this has something to do with with the 0:04:05.760 --> 0:04:08.360 difference between, um, the kind of energy that you want 0:04:08.360 --> 0:04:11.080 to use when you're first starting a car, when you're 0:04:11.080 --> 0:04:15.840 accelerating it from a stop, and when you're speeding up 0:04:15.960 --> 0:04:17.720 later on down the line, right, and when you're when 0:04:17.720 --> 0:04:20.800 you're reaching your top speed as well. Yeah, as it 0:04:20.839 --> 0:04:24.080 turns out, an engine only has a very narrow range 0:04:24.760 --> 0:04:29.360 at which it's operating with its revolutions per minute. Relatively 0:04:29.600 --> 0:04:33.359 narrow range. Uh. And if our vehicles worked within that 0:04:33.440 --> 0:04:37.280 same narrow range, we'd be fine, right, if everything was ideal, 0:04:37.360 --> 0:04:40.000 If somehow the range of the engine and the range 0:04:40.080 --> 0:04:42.800 of the motion of the wheels had a one to 0:04:42.880 --> 0:04:47.000 one ratio, whether it was directly uh, analogous, or you 0:04:47.000 --> 0:04:49.400 had to have some sort of gear shift in there too, 0:04:49.760 --> 0:04:52.480 uh to adjust it. We'd be all right, we wouldn't 0:04:52.520 --> 0:04:56.120 need a transmission, but we really need a wider range. 0:04:56.440 --> 0:04:59.560 And the two things that are really important when it 0:04:59.600 --> 0:05:02.599 comes to operating vehicles, uh, for for the purposes of 0:05:02.680 --> 0:05:06.760 this conversation, are speed and torque. Okay, so so what's 0:05:06.760 --> 0:05:10.960 so what's what? What is torque? Torque is is you 0:05:11.000 --> 0:05:13.440 can think of it as a twisting force. It's a 0:05:13.560 --> 0:05:18.680 rotational force. So whenever you have a wheel turning, Uh, 0:05:18.880 --> 0:05:22.440 it's it's powered, it's that's that's that's torque there. Or 0:05:22.520 --> 0:05:24.800 if you're using a wrench, let's say that you need 0:05:24.839 --> 0:05:27.599 to loosen or tighten a bolt with a wrench, you're 0:05:27.680 --> 0:05:31.279 using torque. It's this rotational force. The the end of 0:05:31.320 --> 0:05:34.279 the wrench is moving in a circle and the bolt 0:05:34.400 --> 0:05:37.279 is acting as sort of the axis of this of 0:05:37.360 --> 0:05:40.480 this pit or a pivot point for this motion. Uh. 0:05:40.520 --> 0:05:44.320 That's torque. And by increasing or decreasing torque, you can 0:05:44.880 --> 0:05:46.720 It's kind of what people talk about when they're talking 0:05:46.720 --> 0:05:49.840 about the grip on the road. Um, you can have 0:05:50.000 --> 0:05:54.080 a vehicle that has really high torque uh and really 0:05:54.080 --> 0:05:56.360 low speed. You can have a vehicle has really has 0:05:56.440 --> 0:05:58.640 speed really low torque. You can have lots of different 0:05:58.640 --> 0:06:02.480 combinations here. So for example, bowl imagine a giant crane 0:06:02.839 --> 0:06:05.680 that you would use in a construction field. All right, 0:06:05.720 --> 0:06:09.320 so it's enormous and it's using wheels, not not treads 0:06:09.400 --> 0:06:12.480 or whatever. Uh, this vehicle is going to have an 0:06:12.560 --> 0:06:15.520 enormous amount of torque applied to the wheels in order 0:06:15.560 --> 0:06:18.440 to move this massive vehicle around. It may not be 0:06:18.480 --> 0:06:21.640 moving quickly, but the torque is really powerful, which means 0:06:21.680 --> 0:06:25.120 that it would require a lot of force to make 0:06:25.160 --> 0:06:28.520 sure that those wheels don't turn if the engine were 0:06:28.560 --> 0:06:31.160 operational and it was being put into drive. So if 0:06:31.160 --> 0:06:33.159 you were trying to hold those wheels still, you would 0:06:33.200 --> 0:06:35.560 have to use an enormous amount of force to counteract 0:06:35.640 --> 0:06:39.960 that torque. You could also have a toy, let's say 0:06:40.000 --> 0:06:42.240 that has a little spinning element to it that spins 0:06:42.279 --> 0:06:45.760 at an incredible rpm. But it doesn't do so very 0:06:46.360 --> 0:06:48.080 with very much torque at all. So if you just 0:06:48.240 --> 0:06:51.240 touched it, it would stop spinning and it would just 0:06:51.240 --> 0:06:53.919 be the lightest touch to counteract that torque. Again, the 0:06:53.960 --> 0:06:58.240 torque is not very strong with that particular device. So 0:06:58.560 --> 0:07:01.240 when we're operating our vehicles, we actually need a fairly 0:07:01.320 --> 0:07:05.120 wide range of torque, which is not something that would 0:07:05.160 --> 0:07:08.000 be possible if we had to work within the narrow 0:07:08.000 --> 0:07:10.280 parameters of what an engine is able to put out 0:07:10.320 --> 0:07:12.320 with that range of our pm. Right, if an engine 0:07:12.360 --> 0:07:16.119 only had one speed, it would get really messy, really fast, 0:07:16.280 --> 0:07:19.520 right and exactly. And you know, the vehicle might operate 0:07:19.600 --> 0:07:23.240 fine in certain conditions, but if you change those conditions 0:07:23.280 --> 0:07:25.920 at all, then you'd be in trouble. And see, that's 0:07:25.920 --> 0:07:28.840 the that's the issue, right because we all know when 0:07:28.880 --> 0:07:32.600 you're out there driving, not everything is a perfectly flat highway. 0:07:33.000 --> 0:07:34.840 You know you're going to have inclines, You're gonna have 0:07:35.400 --> 0:07:38.000 changes in the in the environmental conditions that are going 0:07:38.040 --> 0:07:41.360 to require your vehicle to adjust as you are going 0:07:41.360 --> 0:07:43.760 through them. So that's why you need to have a transmission. 0:07:43.760 --> 0:07:46.960 You have to have something where you can shift to 0:07:47.080 --> 0:07:51.560 a different torque or speed in order to one maintain 0:07:51.600 --> 0:07:53.840 your grip on the road and continue moving at the 0:07:54.080 --> 0:07:58.920 appropriate speed and to operate within the engine's parameters. That's 0:07:59.000 --> 0:08:00.960 one of those reasons why, Like, if you keep revving 0:08:01.000 --> 0:08:03.160 the engine and you're in first gear, you'll see that 0:08:03.240 --> 0:08:05.200 needle go all the way into the red and then 0:08:05.360 --> 0:08:07.240 if you keep that up, you burn out your engine. 0:08:07.320 --> 0:08:11.520 So by shifting, you are actually adjusting torque and speed, 0:08:11.880 --> 0:08:14.920 and by doing that you can keep the needle in 0:08:15.000 --> 0:08:19.920 the the ideal operational Yes, so that's what the transmission 0:08:19.960 --> 0:08:22.680 is for. It's for keeping you in this in the 0:08:22.720 --> 0:08:28.000 sweet spot. And there are, of course manual transmissions, automatic transmissions, 0:08:28.040 --> 0:08:32.079 there are variants of those UM and UH. And while 0:08:32.120 --> 0:08:34.760 we're really focusing on manual transmissions, if we were to 0:08:34.760 --> 0:08:38.439 talk about automatic I think I would have to call 0:08:38.559 --> 0:08:41.040 someone else in because yeah, we would need scotten here, 0:08:41.080 --> 0:08:44.000 because it's a little bit beyond what we are certainly 0:08:44.040 --> 0:08:47.440 our personal technical level with the automotive industry. Not to 0:08:47.440 --> 0:08:49.480 mention the fact that I don't know how I would 0:08:49.600 --> 0:08:52.640 explain it in words without the benefit of pictures. It's 0:08:52.640 --> 0:08:55.480 already given an interpretive dance, and that works less well 0:08:55.520 --> 0:08:58.560 on podcasts. You might you might hear us like with 0:08:58.880 --> 0:09:01.400 by the microphone, but it kind of loses something in 0:09:01.440 --> 0:09:05.720 the translation, right. But so originally automobiles only had two 0:09:05.760 --> 0:09:09.720 forward gears in one reverse, so, but they're the engine 0:09:09.760 --> 0:09:12.960 capacity was much less, so so those narrow ranges were 0:09:13.240 --> 0:09:17.200 kind of okay within two gears. UM. Around the early 0:09:17.280 --> 0:09:21.360 nineteen forties late nineteen thirties, um Ford and Chrysler started 0:09:21.360 --> 0:09:25.440 introducing semi automatic gears that would let you UM. You 0:09:25.480 --> 0:09:27.560 still had to use a clutch, but you could, but 0:09:27.640 --> 0:09:31.600 you could switch between them between the higher gears semi automatically. 0:09:32.480 --> 0:09:35.960 UM in the nineteen fifties, the first full automatics were debuted, 0:09:36.360 --> 0:09:38.400 and UH and then after that, all of the advances 0:09:38.400 --> 0:09:40.880 have been in the in the number of speeds, the 0:09:41.000 --> 0:09:43.679 number of gears that are involved in these transmissions. So 0:09:43.920 --> 0:09:46.240 we went from we went from two up to UH 0:09:46.320 --> 0:09:49.480 four speed manuals, and then six speed manuals started hitting 0:09:49.559 --> 0:09:53.199 the market in the late nineteen eighties. Right, so UH, 0:09:53.240 --> 0:09:55.880 and you might wonder why do you have why why 0:09:55.920 --> 0:09:59.160 do you add more of those divisions, more of those speeds. 0:09:59.320 --> 0:10:01.600 It doesn't necess sarily mean that the vehicle is going 0:10:01.600 --> 0:10:04.720 to go faster than earlier vehicles. It does mean that 0:10:04.720 --> 0:10:08.240 the transitions between between the different speeds or the different 0:10:08.240 --> 0:10:12.600 gears becomes a little more smooth because you've you've refined them, 0:10:12.640 --> 0:10:14.520 you've you've made it a little more precise, all right. 0:10:14.600 --> 0:10:18.280 It lets the engines work less hard at the specific 0:10:18.280 --> 0:10:20.160 task that you were asking them to do at the time. 0:10:20.679 --> 0:10:23.920 Along these lines, just just about a couple of days 0:10:23.960 --> 0:10:26.320 ago as of the recording of this podcast, in mid April, 0:10:27.760 --> 0:10:30.559 GM and four General Motors of course and Ford announced 0:10:30.559 --> 0:10:33.080 that they're going to to work together to develop nine 0:10:33.120 --> 0:10:37.520 and ten speed transmissions. I'm assuming those are automatic transmissions 0:10:37.520 --> 0:10:39.840 at this point, because that sounds like a very large gearshift. 0:10:41.480 --> 0:10:43.800 That will you know, for for consumer vehicles, and that 0:10:43.840 --> 0:10:46.959 will uh, you know, save gas mileage. It could it 0:10:46.960 --> 0:10:49.360 could raise gas mileage by five to ten percent, which 0:10:49.400 --> 0:10:52.240 is you know, not non insignificant, right, and then you're 0:10:52.240 --> 0:10:55.120 talking about decreased environmental impact. There are a lot of 0:10:55.120 --> 0:10:58.800 other benefits that roll out through these, uh some people 0:10:58.880 --> 0:11:02.000 might call them all evolutionary changes, but they can make 0:11:02.080 --> 0:11:05.520 a big difference down the road. Did not mean to 0:11:05.520 --> 0:11:08.120 do a pun there, and one goes out the crystal 0:11:08.200 --> 0:11:10.600 edge accidental puns. We don't we don't need any of those. 0:11:10.640 --> 0:11:12.400 Don't mean to do it, all right, So so you 0:11:12.480 --> 0:11:15.920 might be thinking, all right, how does this whole torque 0:11:16.160 --> 0:11:18.920 shifting thing work. And we're gonna get into the actual 0:11:19.600 --> 0:11:23.360 mechanics literally of it in a little bit, but in general, 0:11:23.920 --> 0:11:26.920 think of two gears, all right. If you have two 0:11:26.920 --> 0:11:29.840 gears of the same size and they are they have 0:11:29.920 --> 0:11:33.440 teeth that interlock. When you turn one gear, the other 0:11:33.480 --> 0:11:35.679 gear is going to turn at that same rate. It's 0:11:35.679 --> 0:11:37.560 going to be the same number of revolutions per minute 0:11:37.559 --> 0:11:39.880 because they are the same size, same same number of teeth, 0:11:39.920 --> 0:11:42.760 all that kind of stuff. Now, let's say that you 0:11:42.880 --> 0:11:47.120 have a large gear and a smaller gear and they 0:11:47.120 --> 0:11:50.440 are interlocking, and you're turning the large gear, that smaller 0:11:50.440 --> 0:11:53.520 gear is going to do more revolutions per minute than 0:11:53.559 --> 0:11:55.880 the large gear. You know, when you go from the 0:11:55.960 --> 0:11:58.199 starting point all the way back around to the starting 0:11:58.240 --> 0:12:00.240 point in the large gear, the small one may have 0:12:00.360 --> 0:12:03.560 turned three or four times, depending upon the ratio between 0:12:03.600 --> 0:12:06.440 the two. Right, same thing. If you have a small 0:12:06.520 --> 0:12:08.760 gear in a large gear and you're turning the small gear, 0:12:08.920 --> 0:12:11.439 you're gonna have to turn that small gear several times, 0:12:11.480 --> 0:12:13.120 you know, to get one of the large gear to 0:12:13.280 --> 0:12:16.400 go around right exactly. And and these these differences in 0:12:16.480 --> 0:12:20.480 speed also result in a difference in torque. So that's 0:12:20.520 --> 0:12:23.000 what's going to become important when we start talking about 0:12:23.400 --> 0:12:27.400 the actual process of shifting and what's going on with 0:12:27.480 --> 0:12:30.080 the transmission. For us to understand that, we're really gonna 0:12:30.080 --> 0:12:32.960 have to take a look at the entire drive train 0:12:33.040 --> 0:12:37.720 of a vehicle, which is both exciting and intimidating to me. 0:12:38.520 --> 0:12:40.400 I think, so, I think it's really cool. It's this 0:12:40.480 --> 0:12:43.160 is this is really entertaining physics to me because I 0:12:43.160 --> 0:12:46.480 have I have. I mean, Jonathan doesn't really drive. No, 0:12:46.679 --> 0:12:49.680 Jonathan doesn't drive. Don't. Don't even bother putting the word 0:12:49.679 --> 0:12:52.600 really in there. Jonathan does not drive. We wait, we 0:12:52.679 --> 0:12:57.920 fortunately have a limitedly robust public transports. I can get 0:12:58.320 --> 0:13:00.400 I can get generally to where I need to go. 0:13:01.400 --> 0:13:03.640 Um uh, And I do drive, but I'm a very 0:13:03.760 --> 0:13:06.560 I'm not I'm not particularly a car person. So but 0:13:06.600 --> 0:13:08.720 this is so, this is going to be an exciting Yes. 0:13:09.040 --> 0:13:12.920 I will ask Lauren about her experiences with manual transmissions 0:13:13.000 --> 0:13:15.520 later on in the podcast, so stay tuned to find 0:13:15.600 --> 0:13:19.760 out about Lauren's own personal adventures with this technology before 0:13:19.800 --> 0:13:23.120 we actually get into how this works in a real 0:13:23.160 --> 0:13:26.120 life setting, what the process is when you're shifting. I 0:13:26.160 --> 0:13:29.040 need to take just a quick break to thank our sponsor. 0:13:29.880 --> 0:13:33.640 All right, let's get back to how transmissions actually work. 0:13:33.720 --> 0:13:35.559 So to do this, we have to look at the 0:13:35.840 --> 0:13:39.839 entire system that makes the car go. All right, and 0:13:40.000 --> 0:13:42.960 and you're you're only interacting in this five speed manual 0:13:42.960 --> 0:13:45.280 transmission that we were talking about with with two bits 0:13:45.280 --> 0:13:48.360 of the clutch and the gearshift. Yeah, yeah, But but 0:13:48.400 --> 0:13:51.880 there's a lot going on under this, Yes, a whole lot. 0:13:52.280 --> 0:13:54.480 And so first we need to just understand what these 0:13:54.559 --> 0:13:58.640 what these different parts are. So you've got your car's engine, 0:13:59.000 --> 0:14:02.920 this is the thing that makes it go. Ultimately, as 0:14:03.000 --> 0:14:06.280 you are depressing the gas pedal, you are putting in 0:14:06.320 --> 0:14:08.640 more fuel to the engine, which is then generating more 0:14:09.200 --> 0:14:12.360 uh power. It creates more kinnetic energy in the form 0:14:12.400 --> 0:14:15.720 of the pistons moving up and down. Those pistons are 0:14:15.760 --> 0:14:21.120 connected to a crank shaft which converts the reciprocating motion 0:14:21.200 --> 0:14:24.080 that's the up and down motion of the pistons into 0:14:24.320 --> 0:14:29.240 rotary motion, meaning it's turning into turning in a circular pattern. Now, 0:14:29.320 --> 0:14:32.720 so the crank shaft goes from the up down motion 0:14:32.760 --> 0:14:35.440 to the rotation motion, which is the very basis of 0:14:35.720 --> 0:14:39.920 everything else that's going to happen. Now, the crank shaft 0:14:40.280 --> 0:14:44.880 connects to a flywheel. Now, the fly wheel transmits this 0:14:44.960 --> 0:14:48.880 rotary rotary motion to a clutch plate, and the clutch 0:14:48.880 --> 0:14:52.480 plate is what eventually connects to that clutch pedal. Yeah. Yeah, 0:14:52.520 --> 0:14:55.200 In fact, there's a pressure plate that is pressed up 0:14:55.240 --> 0:14:57.920 against the clutch plate, right. So the pressure plate, when 0:14:57.920 --> 0:15:01.640 it's in contact with the clutch plate, allows this rotary 0:15:01.720 --> 0:15:04.800 motion to transmit through the rest of the of the 0:15:04.880 --> 0:15:08.720 vehicle's drivetrain. So when these two things are in contact 0:15:08.720 --> 0:15:12.680 with one another. Uh, as long as the engine is going, 0:15:12.880 --> 0:15:17.880 then there is some sort of rotation being transmitted at 0:15:17.920 --> 0:15:20.960 that point, assuming you're not in just a neutral So 0:15:21.680 --> 0:15:23.320 what happens when you hit the clutch, Well, when you 0:15:23.360 --> 0:15:27.320 hit the clutch, the pressure plate rises up off of 0:15:27.720 --> 0:15:31.800 lifts off the clutch plate. Once the pressure plates separates 0:15:31.800 --> 0:15:35.240 from the clutch plate, all power is cut off to 0:15:35.320 --> 0:15:38.800 the rest of the transmission, the rest of the transmission exactly. So, 0:15:38.800 --> 0:15:41.760 so while the engine is still going, uh, it is 0:15:41.800 --> 0:15:46.800 not providing rotary force to the transmission and wheels, which 0:15:46.840 --> 0:15:49.920 is what allows you to shift gears exactly without making 0:15:49.920 --> 0:15:52.200 things explode. All right, this is why you why if 0:15:52.200 --> 0:15:55.760 you're driving a manual, you know, driving stick, you have 0:15:55.800 --> 0:15:58.600 to hit the clutch first because that ends up pulling 0:15:58.600 --> 0:16:00.680 that pressure plate off so that you are able to 0:16:00.920 --> 0:16:05.080 shift gears without making the horrible grinding noise and destroying 0:16:05.120 --> 0:16:08.720 your big brother's vehicle. Uh, I say big brother because 0:16:08.760 --> 0:16:12.560 I know a guy who did do that. Yeah, I 0:16:12.600 --> 0:16:16.080 was not there, thankfully. So assuming that the clutch plate 0:16:16.080 --> 0:16:18.480 and pressure plader are in contact with one another, you 0:16:18.480 --> 0:16:21.320 you have not just hit the clutch um it has 0:16:21.400 --> 0:16:27.000 been providing that rotary motion to the gearbox shaft. Now, 0:16:27.040 --> 0:16:31.520 the gearbox consists of several parts itself. You've got the uh, 0:16:31.840 --> 0:16:34.240 the main well. You've got a lay shaft which is 0:16:34.240 --> 0:16:37.480 connect to that gearbox shaft. You've got a main shaft, 0:16:38.080 --> 0:16:41.720 and you've got several gears attached to both. You also 0:16:41.760 --> 0:16:44.920 have something that's either called a dog clutch or a collar, 0:16:45.080 --> 0:16:48.160 depending upon who you're talking to. And that is what 0:16:48.360 --> 0:16:51.880 is connected to a selector mechanism, which, in the case 0:16:51.920 --> 0:16:54.040 of most vehicles we think of as the stick shift, 0:16:54.040 --> 0:16:58.960 the manual shift. So, uh, the lay shaft is has 0:16:59.000 --> 0:17:02.160 got gears that are are actually part of that shaft. 0:17:02.720 --> 0:17:06.280 They're they're they're splind spleened, spleened. It's probably not the 0:17:06.320 --> 0:17:09.480 correct pronunciation, and I'm going to assume it's splind directly 0:17:09.560 --> 0:17:12.840 to the shaft. In other words, it's got a direct attachment. 0:17:13.240 --> 0:17:16.480 So as the chaft turns, so do the gears. Those 0:17:16.520 --> 0:17:20.399 gears have teeth along the edges and they interlock with 0:17:20.520 --> 0:17:22.680 gears that are on the main shaft. But here's the 0:17:22.720 --> 0:17:24.679 big difference between the gears on the lay shaft and 0:17:24.720 --> 0:17:26.840 the ones on the main shaft. The gears on the 0:17:26.840 --> 0:17:29.880 main shaft are mounted on ball bearings, so they can 0:17:29.920 --> 0:17:33.360 spend freely around the axis of the main shaft without 0:17:33.480 --> 0:17:35.760 actually turning the main shift right. They're just kind of 0:17:35.800 --> 0:17:38.879 ghosting along over it until they become connected to the 0:17:38.920 --> 0:17:41.840 shaft through another piece of technology. Yeah, that would be 0:17:41.840 --> 0:17:46.360 the collar or dog clutch. Now, this is attached directly 0:17:46.400 --> 0:17:48.399 to the main shaft. It can slide to the left 0:17:48.520 --> 0:17:51.639 or right along the main shaft, but if it turns, 0:17:51.920 --> 0:17:55.800 the main shaft turns, so by interlocking the color with 0:17:55.960 --> 0:17:58.920 the side of one of these main shaft gears. Both 0:17:59.040 --> 0:18:01.280 both the collar and into the main shaft gears have 0:18:01.440 --> 0:18:04.000 teeth have teeth along the sides of them so that 0:18:04.080 --> 0:18:07.600 I can interlock. Yeah, exactly, So, so imagine that I 0:18:07.640 --> 0:18:09.800 think of it this way. You've got a gear that's 0:18:09.840 --> 0:18:12.560 got teeth along the outer edge, like a like you 0:18:12.560 --> 0:18:15.359 would see in a typical gear. But you also have 0:18:16.080 --> 0:18:18.800 if you're looking at it from from one of the sides, 0:18:18.920 --> 0:18:21.400 so you're not looking at it headlong, You've turned it sideways, 0:18:21.440 --> 0:18:22.919 so you're looking at it like, you know, like a 0:18:22.960 --> 0:18:26.119 plate you're holding it up, it would have teeth and 0:18:26.160 --> 0:18:29.560 holes along the surface that you're actually looking at, and 0:18:29.600 --> 0:18:32.639 those interlock with the collar or dog clutch, right, they 0:18:32.720 --> 0:18:35.040 kind of sandwich together. Right, So what happens is the 0:18:35.080 --> 0:18:38.840 lay shaft gears turn. That makes the main shaft gears turn, 0:18:38.920 --> 0:18:42.760 and if the collar is is engaged in that particular 0:18:43.200 --> 0:18:47.520 main shaft gear, then the main shaft turns. Uh. I know, 0:18:47.560 --> 0:18:49.800 it sounds really confusing. It's a little difficult to get 0:18:49.840 --> 0:18:53.160 across without having visual effects. We will, by the way, 0:18:53.280 --> 0:18:56.840 link on Facebook two pictures and videos of this, so 0:18:56.880 --> 0:18:59.960 it makes it easier to to to visualize and understand. 0:19:00.640 --> 0:19:03.359 But once you've got that main shaft turning, that's what 0:19:03.520 --> 0:19:08.320 then provides rotary motion to the differential. The differentials job 0:19:08.520 --> 0:19:12.480 is to to turn that rotary motion ninety degrees because 0:19:12.480 --> 0:19:15.840 at this point before you hit the differential, that rotation 0:19:16.240 --> 0:19:20.240 is perpendicular to the wheels, which would not work. You 0:19:20.240 --> 0:19:23.280 wouldn't get the wheels to turn that way. Not very useful. Now, yeah, 0:19:23.320 --> 0:19:26.480 you have to turn that rot rotation, that motion to 0:19:26.960 --> 0:19:28.840 be parallel with the wheels in order to get them 0:19:28.840 --> 0:19:31.080 to turn, so you can go forward or backward, depending 0:19:31.119 --> 0:19:34.679 upon which gear is is engaged. So the differential is 0:19:34.960 --> 0:19:38.159 a set of gears that transmits this ninety degrees, so 0:19:38.200 --> 0:19:41.840 you can do that again. This is your basic five 0:19:41.880 --> 0:19:46.600 speed manual transmission with rear wheel drive. So that's the 0:19:46.760 --> 0:19:51.000 basic layout. But what's going on with the transmission alright? 0:19:51.040 --> 0:19:53.120 So remember I said that you had the lay shaft 0:19:53.359 --> 0:19:55.680 and the main shaft, both which have gears on them. 0:19:56.080 --> 0:19:59.920 So imagine that the lay shaft gears are set ups. 0:20:00.240 --> 0:20:03.720 It's gears that are increasing in size as you go 0:20:03.840 --> 0:20:07.360 from gear one to gear five, and then you have 0:20:07.960 --> 0:20:12.000 that your your final gear on that shaft is for reverse. 0:20:12.000 --> 0:20:13.800 It's about the same size as the one that's going 0:20:13.800 --> 0:20:16.399 to be on the main shaft. Along the main shaft, 0:20:16.440 --> 0:20:19.040 of course, the gears are going to be in reverse 0:20:19.359 --> 0:20:22.520 order of size. So for the small lay shaft gear 0:20:22.640 --> 0:20:25.720 you have a large main shaft gear. The next main 0:20:25.760 --> 0:20:27.920 shaft gear is a little smaller, the next one a 0:20:27.960 --> 0:20:30.600 little smaller and a little smaller. So by the time 0:20:30.640 --> 0:20:33.000 you get to fifth gear, you've got a large lay 0:20:33.040 --> 0:20:37.439 shaft gear and a small main shaft gear. This is 0:20:37.440 --> 0:20:40.359 all because of that that relationship between speed and torque 0:20:40.359 --> 0:20:43.320 I was talking about. So if you've got a small 0:20:43.440 --> 0:20:46.480 lay shaft gear turning a large main shaft gear, that 0:20:46.560 --> 0:20:49.160 means that the larger main shaft gear has more torque 0:20:49.240 --> 0:20:53.040 but less speed. So that's important. When you are accelerating 0:20:53.080 --> 0:20:55.919 from a stop so your car has not started moving, 0:20:56.160 --> 0:20:58.720 you want to engage that small gear on the lay 0:20:58.720 --> 0:21:01.640 shaft to turn the large gear on the main shaft 0:21:01.920 --> 0:21:06.080 so that you will start to accelerate from a stopped position. Now, 0:21:06.160 --> 0:21:08.760 once you start speeding up, you are eventually going to 0:21:09.520 --> 0:21:12.439 require the engine to do more more work than what 0:21:12.520 --> 0:21:14.600 it is comfortable doing. That's when you need to shift 0:21:14.760 --> 0:21:18.200 to second gear, which will be a decrease in torque 0:21:18.280 --> 0:21:21.280 but an increase in speed, And it's because that gear 0:21:21.400 --> 0:21:23.800 ratio has changed. The lay shift gear is a little 0:21:23.880 --> 0:21:26.280 larger for gear too, and the main shaft gears a 0:21:26.320 --> 0:21:29.000 little smaller for gear too. That's where you get that 0:21:29.119 --> 0:21:32.160 change in torque and speed. And this is true for 0:21:32.160 --> 0:21:35.640 for each speed step up, for each gear step up. Yeah, exactly. 0:21:35.680 --> 0:21:38.520 So once you get up to gear five, that's when 0:21:38.560 --> 0:21:42.399 you're going really really fast, but don't yeah, about as 0:21:42.440 --> 0:21:45.800 fast as the engine can hand out without you know, 0:21:45.960 --> 0:21:49.840 having you drive off a cliff dukes of hazard style, 0:21:50.040 --> 0:21:52.600 in which case gravity takes control in your acceleration is 0:21:52.600 --> 0:21:57.879