Clutch Components and Friction ft. D'Amico and Lopes

Harnek and Ian are joined by the one and only Jason D'Amico and the powertrains guru Alister Lopes for a conversation about clutch components and how friction plays such an important role. Be sure to listen to the end as we ask your professors some fun questions that give you more insight on who they really are!

If you have any content or discussion topics contact us at icampbell@centennialcollege.ca. 

Cheers folks!

Transcript

0:04

Welcome to the Talking with the School of Transportation podcast with your hosts Ian Campbell and Harnett Gill. Let's get into it now. Welcome back to the Talking with the School of Transportation podcast. I'm Ian Campbell here as always with Harnett Gill. Welcome, folks. We got joining us today uh Jason D'Amico and Alistair Loops. Hey, good day, guys. Thanks for having us. How's it going, everyone? So, Alistair, what do you teach here at Centennial College? Oh, and I think we're presented by Centennial College now. We got the approval. Yeah. Oh, we're fancy. We're official. No, I didn't get the memo. Yeah, but now with Mr. D'Amico here, I'm not sure how that approval is. Funding's been slashed. Yeah. There's funding? I mean for some other one. Alistair, what do you teach here? So I teach uh for the AST day release program. Um my my uh majority of the time I've been teaching has been drivetrains, uh, level one, two, and three. And right now they've moved me into fuels and electrical for level one and level three so far. So it's uh it's good. Uh I enjoy it. Beyond that, though, you've taught night release level three. So yeah, I did let night release level three, which was everything level three. I've done a handful of level one courses, level two courses. So I've uh been around the block, so to speak. What's your preferred course? I really do like electrical, uh level three, because uh the students are a little bit more advanced in terms of theory, and you can kind of uh you know throw diag at them for the classroom, and uh they really get their heads scratching in the lab. They're like, what's going on here? Okay. And Jay, you're relatively new here, right? So you haven't thought much. Yeah, almost almost pushing two decades. I'm getting a handle on this now. Yeah, 18 years. Wow. Wow. So yeah, I'm starting to feel a little comfortable coming out of my shell a bit. I'm working on it. That's not like you. You're no, no, I know. But my you know, I gotta open up a bit every now and then. I'm trying. For those of you that haven't had Mr. Domico, he's the guy that yells in the hall really loud. Also yells in the rooms, yells in my car. He actually doesn't have a microphone right now. He's in the other room. I don't need one because you're hearing where he is right now. I'm over in A block. Can you guys see me okay? So a better question for you is probably what haven't you taught? Oh, yeah. Um, I don't I don't think there's an answer for that. Okay. Uh every subject, every area, apprenticeship, diploma programs, co-op, a little bit of auto-body when the need arises. I can't think of anything top of my head. I rotate around a lot. How about math? Yeah, I have not taught any of the uh non-mechanical subjects. Okay. Lucky you. Yeah, give me the electrical, the powertrains, suspension, air conditioning, engines, all that stuff. But yeah, I haven't been put in any of the fluid power and newer programs or post-secondary electives, nothing like that. Yeah. And do you have a course you prefer to teach? Uh I don't think anyone's ever asked my opinion when they make my timetable. I guess if if I if I had uh a say in it, uh probably just because of the structure of the labs, I I'd have to go like level one, level two engines. Okay. Right? Uh same powertrains is almost identical, right? Yeah, yeah. Like the equipment we have, the bench space, and all the teardowns. Probably powertrains and engines. Those have got to be my my two favorite subjects, strictly because of the lab content. Great. Perfect. I like it. Well, since you said powertrains and Alistair, you talk you teach mainly powertrains. Yep. I think we'll talk about clutches today. Because I saw a meme the other day. I think Alistair, you showed it to me. Yeah, yeah. And it was this guy with a really jacked calf on his left leg. Mustang owner? Yeah, mustang owner. I'm feeling like it. Mechanical clutch, other legacy. No, the mechanical clutch and and the heavy spring force. Yeah. That's the 5-0 driver. Fox bodies. So clutches. Like you teach clutches level one, that's the starting point, I believe, isn't it? Yeah, well, we get into like the fundamentals of friction and you know, fluid and stuff like that, and then we get into how clutch works because if you don't know the basics, then it's not going to make any sense to you. So yeah, we start off with clutches. The thing I like in the Drivetrains lab is we have some really good um recently some new mock-ups or you know uh training aids. So there's a clutch mock-up which you can actually see the pressure plate, the fingers moving and everything. Students can kind of relate because you're talking and I always get this every every year when I teach it, they get confused between like a disengaged and engaged clutch. Pedal on, pedal down or pedal up. They're like, Oh, well, sir, what do you mean? No, there's uh we have to figure out is it engaged or disengaged? Is it this, you know, are you pushing on the pedal or release the pedal? So something like that with that mock-up, they can actually see it. And and maybe that turns the wheels. Yeah, but we have the same issue always when you're trying to get across uh insufficient and excessive. Yeah, those those terms just putting them into um a physical reality. There seems to be like always a huge disconnect. That's true. And the clutch is perfect, like clutch disengaged, pedal up, right? Pedal down, clutch disengaged, they bounce back and forth between those to the point where like drawings before we had the mock-ups, I would draw a pedal, a foot, and then I would draw, you know, the two drive members and the driven member, and I would draw the relationship. Look, here's my foot, here's the pedal. Here's what's going on inside that single dry disc clutch assembly. Okay, so even then, it's just hard to get through. For for a student that's disengaged, how would you explain what clutch disengaged means simply? Well played, well played. Yeah. Bounce on words. When you're sitting there in class, you're not paying attention, you're disengaged. Oh, we didn't mean the student, we meant the clutch. Sorry, how would you simplify something? Probably because like if you go by just what you instinctively think right off the bat without knowing, it's the default position of the clutch. Yeah, right. It is fully engaged, at rest, on its own, your leg is hanging out the window. That is the at-rest position. So because they're mechanically changing the position of the pedal, they kind of always lock into the fact, well, if I'm pushing a pedal, I must be disengaging or engaging something. And and they mix the two up all the time. It is a big point of contention. Yeah, kind of counterintuitive to what you think. Yeah, and they're like test questions when I, you know, reviewing that. Okay, guys, the clutch is disengaged. Like, oh sir, but I thought you said her pedals on the foot or not on the foot. Yeah. Well, which one is it? That's up to the phone. It doesn't matter what the pedal's saying, what's the clutch doing at the end? Exactly. I didn't say pedal, I said clutch. Yeah. And and you mentioned friction earlier. And I'm really glad Jay's here because you teach friction so well and the coefficient of friction and what it means in the automobile or just the world. It's that science background and always fix cars, right? Yeah. And what do you what is so important about the COF or friction in general? You know what I it's like I always tell the students, it doesn't matter what subject area, right? I always start out by saying, like, what makes a car work? Like it's a machine, plain and simple, right? No matter what decade you go through, what period, it's a machine. It's gotta obey certain laws, right? So I'll, you know, I'll I'll start out by saying, like, go through high school, think of all the subjects you took, like which two are the most relevant for the job you're doing today, right? And the answer is it's cut and dry. Some students will get it, man. It's a machine, it works off two principles, math and science. It does not work off English, art, poetry, art, music, class, feelings. Yeah, yeah. Well, that's what I always say. I don't I don't lay my hands on the vehicle and and and feel, I don't go with my gut as to what I think is wrong. It's math and science, there's a direct answer. So the better the student can understand like the basic math and science principles, the cars are the easiest thing in the world to work on. They're machines, right? There's there's no randomness to it. There has to be a logical path to whatever your issue is and whatever your corrective response is to repair it, right? So I know I'll take the little bit of a survey too. Like before I give away that tidbit of information, I'll say, Hey, you know, guys, high school, it sucked, nobody liked it. I I get you, it was the worst eight years of my life, too. But then I'll be like, which two subjects did you hate the most? And usually math is the first one, and then science will be the follow-up, and they'll say it's interesting because you guys have chosen a career that is largely based on math and science. So it's your admitted weak point, and you're and you're going into a field that requires it to be your strong point. Yeah. So when you can't get them to make those connections, there's no more kind of gut feelings on cars. Like just get the simple math down pat, right? Get your coefficient of friction, get your kinetic energy, understand your hydraulics laws, your air pressure laws. And that way when you go to diagnose any symptom on the vehicle, you're thinking in those scientific terms, it will lead you to the correct answer. But if you if you don't know the principles and the foundations, you're kind of just diagnostic dartboard at parts. And then that's when your diagnostic approach becomes well, what's the cheapest part to start with? What's the easiest part to change? And then what's next when it doesn't fix that? Yeah, I really like that you said that because it changes from being a diagnostic technician to just being a parts replacer. Yeah. And if you actually understand and can build that knowledge and understand how that component works, it really changes the stuff. Yeah, and I totally get, you know, maybe the industry has changed where we have kind of transitioned to more of a parts replacing industry. But what are you here for? You want to be a technician. Technicians understand, they diagnose. Right? Um, bring out a two-tier system then. Like bring out an installer class license and have hey, you know where that part goes, you know the torque spec, and it's two-hour book time, but you can nail it in one. Great, you're you're an excellent installer. So it's mission, you can stop them and say, Hey, that part in your hand. Tell me everything you know about that part in their operation. Oh, that's yeah, that's the attack, right? It's funny that you said that, having the two-tiered system. I actually had a student, and this is years back when I was teaching night release, he came up to me and said, Sir, I didn't remember what dealership he was working at, but he's like, My service manager just wants me to throw parts at a car. Throw a part at a car, kick it outside, move on to the next one. And eventually that car comes back for the same problem. And he goes, What should I do? And I told him, You should leave that shop. You should go somewhere else where they actually give you the opportunity to die again to figure out how it works and fix it. If all they want is you throwing parts at a car, you're not fixing anything. Problem is though, some places have an incentive for that. Yep. This is the service of the week we're selling, and you know, the whole flat rate structure is counterintuitive to an apprentice learning. Like it shouldn't be there, in my opinion, right? You're there to learn. So learning takes time, right? So I guess my question is what's coefficient of friction? Well, we like coefficient of friction. Like I always break it down to guys, don't get in over your head. Like, let's just look at the root words, like coefficient. That means relationship, right? Friction, uh, forces between bodies at rest or body in motion. Yeah. So great, we're talking about coefficient of friction. It's the relationship between materials, right? And then you get into the math and all that to prove, you know, what's a low COF, what's a high COF. So once you can get, you know, kind of that through, it's like, okay, now we're going to turn it around. These materials. So I'll teach, you know, a low COF, uh, something that works out to be uh pull overweight tensile force divided by wave force of the object. And then you're like, okay, this is 0.1 mu, so it's one tenth COF, right? In English, it would slide very, very easily. And then I'll go with something that's like a 100-pound object, requires 300 pounds of tensile force. All right, it's a 3.0. This does not slide easily. In fact, we're above a 1.0 threshold. Material is going to be exchanged between the two surfaces. And the example of that, you know, I'll throw it out there in class. That's your contact hatch between the tire and the road. So then I'll I'll bring it back to brakes, which everybody, you know, you start on fluids, you get to do some tires, and then you're slapping brake parts on. And I'll ask a simple question: like, so what is the coefficient of your brake linings, your average OEM friction lining with your average OEM rotor? Is it more towards the 110th where it slides very, very easily, or is it more towards like a three-point all like a tire? And and I'll get answers that, oh, it's a very high COF. I'm like, but no, guys, if you understand brakes, like definition of brakes, locking up kinetic energy converted into heat. We need that, and then I have them do the old slide the hands together lightly, feel the heat. I go, that's your brakes, man. You want them to slip to produce that heat because that's how we scrub it away from the vehicle. Can't create matter, can't destroy it, convert it from form to form. So, but it's still like even after the discussion, like the go-to answer is oh, your brakes have a very high friction level. No, man, then we'd all be eating dashboards. Yeah, you'd be afraid to touch that brake pedal. Smashing your teeth. And once they lock up, they do zero conversion. Your tire steps up. And we all know tires aren't very good at being brakes. They're real good like one time. And then the ride's a little rough after that. So yeah, it's kind of like they don't I find a lot of students they don't want to know the science behind stuff. They don't want to know how it works, they just want to get it fixed. But it's like, guys, if you understand like something as simple as friction, now we have clutch complaints, drivability complaints, clutch chatter, right? Combination of mixed COFs. Yeah, you know, it all plays into the diag. Yeah. And for guys that are like uh, well, pad slapper if it was brakes, but for clutches, there's a lot of guys, man, they'll go through the work to drop down the the transaxle or transmission and they throw up just the friction disc. Yep, right? Um, hey, if it came in the kit cheap enough, there's a pressure plate on there. But they leave that first drive member there, that flywheel that's got 300,000 K on it. That surface, it's got the heat checks, it's got the glazing. Slick as anything. Yeah, you're you can't count on one drive member to hold one side of the disc, and the other one's got a COF of next to zero. And then they wonder why, well, the OEM clutch went, you know, 200,000 K, and when we replace clutches, oh, they're gone at 50, they're gone at 40. Must be driver abuse. No, man, you're leaving one slippery part up there. The thing's gonna superheat 1200 degrees Fahrenheit, uh, the clutch is somebody it's lost its friction on one side. So now you're getting by with what, 2,000 pounds of clamping force, but a low COF. It's just a battle of, hey, this thing's done at 20k again. Yep. Or if it's someone who's learning how to drive stick. Yeah. Yeah. Well, you know, let's not throw stones. I'm getting better at it. Sorry. Right. Why does it take a clutch? One of the reasons students have difficulty understanding clutches is most cars today are not equipped with a manual transmission. Yeah. Right. I've heard of like a lot of stories where someone breaks into a car to steal the car, they realize it's a manual, and then they leave the car because they don't know how to start it. Yeah, well, they do the new standards and automatic. Yeah, and even as it's been since the 80s, you have to order special order a manual car if you're picking it and if you want that. Well, there's really many manual Wranglers being sold anymore. From a production point of view, there's absolutely no advantage to a manual. Like manual technology was as great as it was going to be 1990. Yeah, you had your your Synchro Mesh GM uh synchro assemblies, that was about the pinnacle of it right there. And maybe they threw in uh speed sex. That was it, man. But automatics, you cannot out-shift an automatic. Of course. No, I've seen Fast and the Furious. They have those manual nine quad transmissions. Any chip can like well, they are either fast or furious. Yeah, you can't do both. Nine reverse gears. But yeah, like when you've got nine speed automatics overrunning two gears at the same time, there is zero shift point. And you can't shift fast fast enough. Nothing's putting up. Yeah, yeah. And then you get your CVTs out there. Yeah. As dry and unexciting as they are, they work. Yeah. So from a shifting performance point of view, you can't beat the automatics. Yeah. And then you add in the retail aspect of it. Who can drive an automatic? Everybody. That's a big factor. It's who's buying the new cars. Who's buying the new cars? Try to find a base model car. They have one advertised, so legally they can say it's $15,000. Yeah, there's one in Ontario. And all the other ones are package C, package D, full power groups. It's what consumers want. Nobody wants a manual. They're useless. I like them, but they're useless. Yeah. You're gonna find it's niche, right? You're gonna have the guys who are spending the money because they enjoy the vehicle. But for a lot of people, having a vehicle, they don't really care about it. It's it's just something that they need to get a manual. And then they don't want to be driving a manual car and stop and go traffic in the city and stuff like that, right? If you're that's your daily commute, you're sitting in half an hour of traffic. But then what's the lifespan of a vehicle now? It used to be the average consumer was seven years. I think it's down to like four now. Yeah. So even if you have the ability to drive a manual and you enjoy manual, think about your resale. Everybody's always wanting to resell stuff these days. Hell, they don't want to lose a penny. They tend to want to make money when they sell it. If you've got a manual, you just cut off 95% of your audience. I do find the people who are buying vehicles with manuals, they do want to keep them long term, though. Yeah, that's not their everyday driver. Yeah, you know, especially if it's like a muscle car or something like that, stored in the garage and see rain, snow. That's the odd guy here or there. The bulk of the driving population, they don't care about that. Well, think of the driving population is like that are buying new cars anyway, 30 and up, right? With families, you're not seeing that manual desire anymore. It's funny when I was at the dealership and I I my background is Chrysler. So I remember way back when we do some of the training, they're like, hey, this RAM comes in manual. I was like, I've never seen a manual RAM before. Sure enough, one day this RAM shows up and it's a six-speed. I'm like, oh, this is like the holy grail. I've never seen this before, ever only heard about it, and finally here's one. But that was like one in my whole career that I've ever seen. Yeah, we had uh we had at the shop. This is going back, you know, quite some time for you guys 1932. Yeah, I'm not sure if you were lied yet, but there was a thing called the Mazda MPV. Oh, yeah, yeah, yeah. Multi-purpose vehicle. Yeah. So we have stands for? Yeah, I didn't know that. Yeah. So we had one, I believe it was all-wheel drive and a manual transmission. I've seen all-wheel drive, I've seen manual, but I've never seen it. There was no such animal ever. Turns out there was like three in North America. Wow. So anytime you call for parts, it'd be like, uh, the dealer would say there's no listing, like those aren't options that exist until you found the right dealership that remembered you. And they're like, is it the green one or the blue one? Because there's only three in the country, man. Yeah. And those are probably crushed. Yeah, and that guy loved that vehicle. I remember he had on uh this is back in the 90s, he had his leather gloves with the fingers cut off, the knuckle holes, his Ray-Ban glasses. Driving the van. Yeah. And here's the thing when something like that then does come in for service, you get a technician who, like you're saying, will replace two of the parts, but not everything. They haven't really thought it through. This is the guy who's really gonna spend the money to fix his car, wants it fixed properly, and then he gets the technician that doesn't know what they're doing. Right? Let alone like he's probably never even seen one before. So how's he gonna fix it? Yeah, well, that's the thing too. Like if you're if you're gonna, I don't want to say half ass, but if you're gonna half ass something, always look at it. Hey, if you don't do this job right, what's the resulting comeback? For sure. Was this a one-hour clutch? Like I can do Volkswagens on the side of the road. So, okay, if you're gonna cut corners and slack and bite the bullet on a comeback, it's an hour of your life gone. Yep. But I've done other units, they're like 12-hour jobs. Yeah, right. Like this thing's gotta be dialed in perfect. You cut no corners, no edges. And then if it's that guy with that one off oddball car and he thinks it's the Ferrari of minivans, yeah, it's gotta be tight. It's gotta be perfect. Yeah, that's true. But you you're saying that, you know, what's this gonna cost you in terms of time? I always talk to students, and when we're talking about fixing it, some like, oh sir, just throw a part at it, that'll fix it. And I said, What if it doesn't? Do you work for free? Because you're gonna on the second time when that car comes back and you haven't fixed it the first time. Yeah, but I find a lot of that stuff is like excuses. Like when we talk about diagnosing a vehicle, they always the list of excuses because I've been hearing them for almost 20 years, they're they're pretty standard and verbatim. One will be is um, I don't get paid enough to diagnose. And then you can you can shut these down pretty easily, and I say, okay, well, hold on, uh, I'll pay you whatever you want. Well, you know what, it it takes too long to diagnose. Hey, buddy, we got all day. Like, so that excuse is gone. Ultimately, if you keep busting their excuses, it comes down to they can't do it. Right. So then just say you don't have the ability, you don't have the knowledge, and that's what you're supposed to learn. But don't try to sugarcoat it with blaming your employer. Oh, he won't pay me enough. Oh, they don't want to look at it. Like, are you a technician or an installer? Yeah. That goes to the two-two system we're talking about before. Well, because we're tying in the retail to skilled labor. So, and I'll tell them all the time, like, guys, on I have a few C of Q's done. Nowhere on any of those exams do I ever remember seeing a dollar sign. Yeah. And nothing about time, it's irrelevant. That's the retail aspect starting to tip in on that, right? So you're supposed to be learning the technical aspect, but the retail clouds it all the time, where now we've got offshore parts that are $30. Right. So, yeah, there is that retail argument of why would we charge one hour diagnosis at $150 an hour when the part is $30? Hey, Identifix is out there, forums are out there. Let's just throw in the $30 part. Yeah, the forums. But then, you know, if that's the route you go, you're gonna be eliminated very shortly because customers can also watch that YouTube video, order that same $30 part. Yeah. Hey, it's 20 minutes to change, and now you wonder why you know your business is starting to go down. You want to have that knowledge and skill, no one else can do, man. You want to set up that final drive and run that pattern. You want to be that guy. You don't want to be the shop that subs that out. But we could be YouTube certified. Yeah. You know, and you know what really grinds my gears? We're doing that all day. I like the back of it. Clutching at straws then. Yeah. Um speak so back to clutches a little bit. Oh, yeah, we're talking about how do they work? How do they work? Yeah. Oh, geez. Oh, which ones are we going for? Hold on. Let me uh let me just uh search this up here on Wikipedia. Give me a second. Well, according to Google, yeah. Yeah. Well your single dry disc clutch? Yeah, just the basic so that again it goes back friction and force. Yeah. Yeah. We have the clamping force and uh and the frictional force between the the the driving members and the driven members, right? So we need to figure out what's what, what's who's connected to who. Yeah. Right? That's uh that's a big battle. So let's list off those driving members and driven members. Let's let's kind of list those off a little bit. All right, so we'll go with our engine crankshaft. That's our torque output. Right? We want to get that torque to the input of the transmission. So our clutch is the middle main in between, right? So no automatics, no torque converters. We don't understand those get those out of the way. So we're gonna look at we need a direct mechanical connection to our crank. That's our first driving member, right? That flywheel. Right. So there's our flywheel. So bolted straight on directly out. Whatever the crank does, flywheel matches, speed and torque wise, 100%, no loss. Then on the other end, we've got our transmission input shaft. Let's put our friction lining on there, our clutch disc. Let's spline that guy on there. Let's have a mechanical connection one to one. Speed is identical, torque is identical. So now we got to get to our pressure plate assembly, our second driving member. That's easy, man. That is bolted to the first driving member, which is bolted to the crank. So crank, flywheel, pressure plate, they all move as one. Speed, torque wise. Now we gotta get it to that clutch disc, which is still a mystery to me to this day, Alistair. It's magic. There's some sort of thing. When is that with witchcraft? Witchcraft you're booting. Yeah, exactly. That's normally what students say on a test, too. Alright, so I got all the mechanical connections covered. So crank, flywheel, and pressure plate, they move as one assembly. Yeah. Crank, flywheel, pressure, pressure plates are all bolted together. Yep. Mechanical can might as well be welded. And that's sandwiching your clutch in the middle of that, which is going to be spline to the transmission, right? So you have two separate setups essentially. Yeah. So no mechanical, no straight mechanical connection of the two drive members or that clutch disc. So it's really going to come down to clamping, force, and friction. It's like if you want to pick up um a 10-pound block without curling your fingers around it. Keep your hands straight and just crush it with pressure and pick the block up without actually grabbing or molding around the block. It's all that's happening there. Yeah. It's a little bit of a drive member sandwich. It's a party. Drive member sandwich. Yeah. That phrase is uh copyright now. Well, so talking about the pressure plate, I always tell the students, you know, there's a ton of pressure that's being applied to that clutch when we engage it. And then I go, what pedal up or down? Oh, they scratch their heads, right? But that's a mystery again. When it's engaged, there's a ton of force. And you know, I can talk till I'm blue in the face in classroom saying, you know, it's 1500 pounds of clamping force or 3000 pounds or whatever the case may be. And then we get to the lab and I actually have a pressure plate flywheel and clutch disc assembly, and I tell them, push on the pressure plate fingers. Are you are you guys strong enough? I picked the biggest guy in class. Hey, push, push on those pressure plate fingers and get the clutches to release. And then they glue in, like, well, there's a lot of force back there. Yeah. So to overcome that, then we talk about mechanical advantage. I don't think we talked about that yet. No, that's true. Because that's another thing that has to do with our clutches and how we can pressure aside with the two drive members crushing that disc, you also got your friction in there, right? And it's static friction. Yep. Static friction is much higher than dynamic, right? So one of the things they'll do is they'll say, hey, you know what? I'll uh I'll leave my house and I'll shift first, second, third, I'll get on the highway and I'll drive three hours straight to Windsor. Right? Just stay in fifth all the way to Windsor. And then I'm gonna get out real quick and reach in that bell housing and grab that clutch. And like, oh, your hand's gonna get burned. No, man, it's static. There's no heat, it's static. And then you know, eventually we compare discs, uh clutch disc assemblies to brakes. Yeah, they're the same linings, yep. Exact same function but opposite ends, man. Brakes love kinetics, statics love uh clutches love static. And then I'll be like, guys, look at the lining on a disc. Like, see how thin they are? Why don't they make them really thick like brake pads? And then guys will scratch their head, right? And they're like, oh yeah, that clutch would last forever. I'm like, but dude, it lasts forever when it's yeah. Yeah, I I think I've put cars in the scrapyard with the OEM clutch stuff. Like, I'll get 500k out of them. So and they're like, Yeah, why is it that thin? I'm like, because it's not doing any work. 95% of its life, it's static. It's just getting sandwiched in there, man. The only time that clutch is gonna wear and those pressure plates and uh flywheel surfaces is when you're slipping the clutch. Yeah, when you're engaging, disengaging, yeah. And then that's kind of a hard one to wrap their head around too, and I compare it to the pedal, right? Yep, and when your mouth is wrong, your hands are right, and we start showing with our hand. I'm like, look, dude, pedal all the way up, top dead center, highest point. I go, nothing's going on with the clutch assembly. Pedal all the way down, like no defects, fully disengaged. The members are physically separated within air gap, nothing's going on. Anytime you are in between top dead center and bottom dead center, you are slipping the clutch. That's the kinetic world. And if you're shifting properly, that should be a quick interaction. Yeah, within five seconds. Yeah, most guys are like, you know, without dumping the clutch, it's like two to three seconds shift. It's practice makes perfect, right? Unless you're resting your foot there and just chilling up. Well, and then though that's another thing I always ask my students. I'm like, hey, if you're driving a manual car, there's three pedals and there's something on the far left. What is that? And like, I don't know. Throw the rest pedal. Yeah, that's where you put your foot in between shifts. Yeah. Throw in the fourth pedal under the dash there. Part headlight switch? No, that was under that one under carpet. That one, no, man. Parking brakes when they used to be on there. Now you got four pedals under a car. So I always tell them, oh, well, one is you know, low speed clutch, and the one on the far left, which are high speed clutch. So you're on the highway, going from bringing it out four to five, man. You stomp that bad boy down. Yeah, so anyway, that's maybe one of the reasons. I never said I was good at this job. I've just been here a long time. So that's why I tell them, you know, anytime you're between top dead center and bottom dead center of the pedal, you're in the slip element, right? And then they go, What is slip? I'm like, well, guys, you've got we said, you know, the two drive members are doing effectively what the crank does. You've got to remember the disc is doing effectively what the tranny does, which is through the gear ratio is the wheels. They're moving at different speeds. So anytime those members don't match up, they are slipping. You have a speed loss. Yeah. And that's going to produce your heat. Right. Which is what the clutch is meant to do for two, three seconds. Yeah. For a certain amount of time, and five seconds we start smelling. Can you quickly just simply one of you guys uh explain static friction versus kinetic friction? Okay, so static friction is friction at rest. Two any two surfaces or any two objects where they're not moving, there's friction and static friction in between. Uh kinetic or dynamic friction is friction of something in motion. So you know, we got it in brakes, we got it in clutches. So your your pads and rotors, right? Sliding friction. Yeah, that's that's that's the difference. And that's the one that also I feel gets my students because I'll ask them, what do we have on a clutch pedal? Do we have static or fruit or kinetic? And they'll say, Oh, we just have static, or some of them would say, just we just have kinetic. No, we have both. What are we doing? It's how you're driving it, right? Depends on the snail. And which of those friction types of friction do we want? We want more static friction than kinetic friction on a clutch disc because the more kinetic friction we have, the more wear we have. Yeah, but we can do the same with brakes too. Like back when we you know had to know how to drive. My brakes normally, under ideal conditions, they're they are a dynamic setup, they're kinetic energy, right? I can easily switch rolls and go static. Yeah, it's brake lockup. So guys know the term brake lockup, but it'll be like, Do you know what brake lockup means? And and I explain the friction, right? I go the pads and the rotors or the shoes and the drums, they become static. There is zero heat exchange, they are turning at one speed, they are locked up, they are one and the same, they are locked up. That's where that term comes from. So a lot of these terms guys throw out if they don't know the origin behind them. So anytime you can kind of make a connection, okay, guys, no brake lockup. Like if you just bring that in class, say guys, what are locked up brakes? And then everybody's gonna go and make the noise. Okay, good. But now what's actually happening there on a scientific level? Like it's a machine. And that's where it kind of, well, nobody knows, right? Well, the brakes are locked. Okay, but what does locked mean? Locked is another way of saying the brakes have gone static. The assembly is static. You no longer have your braking and your tires stepping up. So that's basically kind of summing up the clutch assembly, right? That would be the three driving member or the three. Yeah, we're talking like single drive dish very simple. No dual mass flywheels, no center fugue pressure plates. We can get into that another time. No, we can't. I I just saw those terms on TV. I they sounded cool. I wanted to say them on the radio. I have a list of Google words that I have to talk about today. Baba buooey, baba buoy, baba buoy. Like I guess wanna be on the radio. So I have a question for Harnick, who's not a drivetrain's teacher at all. Nope. Can you sum that up in your own words? Which part? Everything. I'm gonna say like the between the static and the kinetic friction, because I do SSB so much, uh, explain it very much the same way. I do things a little bit different. I just I put my water bottle down on the desk and I say, why isn't this sliding around right now? And you say, Well, between the desk and the water bottle, there's static friction. That's what gives me my traction, right? With kinetic friction, if I'm moving this around, now I have kinetic friction. And then I use that same example of rub your hands together. Yeah, but then the best one is to get warm. Right? I'll draw a picture of a tire and I'll say, here's the tire rolling at 100 kilometers an hour. That's the last portion. But the theory portion, I draw a tire and I'll be like, look, this car's moving at 100 kilometers an hour. How is the tire going? And they'll be like, Well, tire's rolling at 100. I'll be like, Well, actually, it's rolling at 200 because that's the math on that. Right. Like, well, don't worry about that right now. Let's go with you. The car is at 100, the tires at 100. I draw the contact patch, mean tire and the road. What is it? Yeah, and then I'll be like, is this static or dynamic? Dynamic. And because I use the word rolling, rolling in Drew's speed, they'll be like, Well, that contact patch is kinetic. It's like, no, it's static. Yeah, that usually blows their mind. Yeah. The table, the bottle sitting on the table, they get because nothing's moving. Yeah. But then you have a rolling tire, like, yeah, that's also static. Yeah. And then usually if you weed it out, you might get somebody who who actually knows an answer or has an idea. But most of the time you got to explain it. Right. Right? This is why moving tire is actually static. It's always a new portion of the tire meeting a new portion of the road until the brakes are locked up. Until you lock up and you get that switch up. And that's the same thing. I said, what happens to the tire? It gets real hot, just like your hands. Yeah. Now you got that kinetic. And because the COF is above 1.0 material is exchanged. Don't believe me. Look behind you. Black skid marks. Look at your tire. Look in front of you. There's a bumper come up real quick. It's round in 90% of it, circumference, but then it's that one flat section. All right. Speaking of the brakes there, how many feet does it take to stop a car from 60 miles an hour? So your average vehicle, like what? Uh 3,000-pound vehicle? No, two. Two. 2,000 pounds. Two feet. Two clutching the brake. 112 feet. Jay instantly. 112 feet. Let me do math. This is a little flipping math. Yabba yabba doo. Two feet. Is that going to be on the test? Yeah. Yeah. It takes one foot, your driver's foot. But if you want to know distance, is that what we're asking? You know what? I tried doing some research and it just bombed. I'm standing by 112 feet. Okay. But you didn't tell me road can do. Stick to the knock-knock. What's the ambient humidity? Oh my goodness. Okay, let's let's let's. What's this geoweap in your scenario? Are you driving the car? Because that's another 300 pounds a day. It affects my math. No, I'm not 300 pounds yet. I'll get there. You'll get down to there, yeah. You get down to the yeah. All right. Uh at the end of every episode. You buy lunch? Uh well, we're running out of time for that. But for that. Yeah. We could have cut this thing shorter and had lunch. I have two questions. All right. First question for both of you. If you could be one person at any time in the world, uh who would you be? I'm okay with being myself. Is this a trick? You and Colin. We'll take it. Colin. I don't want to be Colin. Colin wanted to be some scientist. Some scientist. Yeah. Oh, yeah, that's right. Is Spider-Man a person? Yeah. Anything. You want to be Spider-Man? That would be a good one. Now it's like with Spider-Man. Yeah, it should be Spider-Man. I think with Batman. That's cool. I can always say no one's ever asked me that question before. That's a good one. Yeah, I also don't put thought into stuff like that. Well, now I'm asking to. No, I'm fine the way I am. Okay. You might have an Optimus Prime Man. I know you want to be Optimus Prime. Now you're like, you know this all the time. But if there's someone that I'd actually want to be, but like maybe just seeing other people, like in like especially like some of the like famous people or like people that have invented things, like seeing how they came up with that, you know, watching them, it's I don't know. It's all aliens. That's Callins. That's what Call Call is. I can't think of anyone that I'm not sure. Why do you guys sound so good? I don't know. I'm on radio. I want to sound good. All right, we may have to change this question up. Yeah, yeah, yeah. It's awful. Okay. If you had one car to drive for the day, anything in the world, what would you pick? I don't like cars. One motorcycle. One anything. One automobile. One vehicle. Yeah, I'm an R I'm an R1 guy. R1? Yeah, it's an R1. I wouldn't mind getting on the new 2023s, 24s. Yeah. It's been a while. That makes sense. Yeah, I think they've made some improvements in the last 20 years. I wouldn't mind taking a stab at it. I'd want to drive. What year neon do you want, Alistair? It's got to be that hunter-green. Gotta be the hunter green. I'd want to drive like one of those like Baja off-road trucks. Well, like a sandrail. Yeah, like sandrail's just going nuts. Oh, yeah, changing my answer. I want uh it's a car rally. Let's go. We go together. Yeah, we're going to the desert. Man, I'm gonna have to think about things now. No, that's good. That was way better than my answer. Yeah. All right. Yeah, do some rail jumping sand dunes? That's cool. Even on the streets of Toronto, I'll just rip it all sidewalks, whatever. It's someone else's car the next day. Yeah, I don't own it, right? I didn't buy it. You're just giving me the keys, right? So yeah, going for a tank ride would be pretty fun too. A tank ride? Yeah. Oh, yeah. Like an old abandoned farm we're at. We're just gonna demo it anyway. Just drive through everything. Yeah. That'd be kind of fun. Watch out for that house. Yeah. One house. Yeah. Well, guys, thank you so much for jumping on the podcast. Yeah, thanks for having us. Thanks for having me. No, no, we can talk about those fancy terms that we don't know. Yeah, once it's good. Yeah, like what was that? Uh centrifugal clutch. Yeah, oh yeah. Centrifugal clutch flywheel, whatever that is. Yeah, whatever. Yeah, okay. Yeah, I think there's more stuff to hit. Yeah, I just saw all the parts counter. It just looked good. So this is it, what this has been the third podcast? Third podcast. I feel privileged to be on so early. I like it. Well, you're a special guy. I'm glad you're here. I was forced. I was promised lunch, though. I mean, I bought it yesterday. That's true. That was my non-contact. Perfect. Guys, thanks so much again. Uh, and until next time, we got to figure out a good We still don't have a good outro. We don't have an outro. Sign off. Yeah. Oh, you want like a catchphrase or something? Yeah. Do you have one? Well, appropriate or catchphrases. Autobots. Autobots rollout. Yeah. That's J copyright. I think that's an issue. They're like, uh, it's one of the ones I always use. And then they start using my catchphrases back. Like when I'm teaching um alignment, especially, right? Oh, see the angle of the dangle. I don't know what those guys are thinking. Yeah, they just that becomes a catchphrase. Yeah, all mine are inappropriate like that. All right. And until next time. Cheers. All right. See you guys. Take care. Bye.