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This is The Strongest Transmission Ever Built - Planetary Manual Lenco Gearbox Explained
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- Published on Apr 17, 2026
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If the algorithm thinks you’re into cars it has probably shown you a video of a planetary manual transmission, aka a Lenco transmission at some point. And many of you have probably wondered what the heck was it that you just saw? But have no fear d4a is here! And today I’m explain what kind of transmission a planetary lenco is and why it exists. I will also explain exactly how planetary gear sets work with a special little model that I made and finally, I will explain why Lenco planetary transmissions are the strongest transmissions ever made.
Transmissions of this kind first started appearing back in the late 60s, early 70s in the USA when engines started to make serious horsepower and torque. Ever more displacement, ever more aggressive camshafts, ever larger superchargers all lead to the fact that race engines of the time started to eat transmissions like cookies. The hydramatics, powerglides and muncies of the time simply couldn’t keep up.
That’s when Leonard Abbot started Lenco, a company manufacturing planetary transmissions for racers. He gave racers everything they wanted. An unbreakable transmission that could shift faster than any manual or automatic and without lifting the throttle or pressing the clutch.
Inside a Lenco transmission you will find this. A planetary gear set. Planetary gear sets consist of three types of gears. The outer ring gear. The inner sun gear. And the planet gears which revolve around the sun gear. Each of the gear types is attached to its own shaft.
An actual Lenco is composed of multiple modules. Each of the modules consists of identical parts and inside each of the modules you will find a planetary gear set. The only difference is that every gear set has it’s own gear ratio.
You get first gear by multiplying the ratios of all the modules together. You pull a lever and you lock the first module. That module is now 1:1. Your gear ratio is now the result of the multiplication of the remaining modules. You keep pulling levers and locking gears until you get your final gear ratio of 1:1. If you have four modules then you have 5 speeds. If you have 5 modules then you have six speeds and so on.
Okay, so why is it so strong? Because a lenco combines the mechanical advantages of a manual with the high number of gear contact points of an automatic.
Let’s think about launching in first gear. This is the moment when you dump the clutch and shock the transmission with a sudden release of thousands of Nm of torque. In a manual transmission in first gear all of our torque is transferred through only two contact points. A single planetary gear set has 6 contact points. If you have a 5 speed Lenco you have 24 contact points. You are not breaking that many gears.
Now in a automatic we also have planetary gear-sets. The engagement of their parts is controlled with clutch packs just like in a Lenco but the clutch packs are controlled by fluctuating hydraulic pressure. On top of this the clutch packs need to slip slightly during engagement to create a smooth shift. In a Lenco the clutch pack engagement is instant and they are clamped down by mechanical force. This ensures a bulletproof engagement and clutch holding.
The other reason behind Lenco’s strength is that all the gears are straight cut as opposed to helical gears found in OEM transmissions. No, straight cut gears are not stronger than helical gears. The problem with helical gears is when you spin them they rotate but the direction of their teeth also creates an axial force. In other words the gear is trying to move along it’s shaft. To absorb these forces helical gears and shafts needs thrust bearings and strong transmission cases. This is why racing transmissions use straight cut gears. They are noisy, just like the straight cut reverse gear in your daily driver but they create zero axial loads which means that you don’t need thrust bearings and you don’t need to worry about tearing your casing apart with your monster engine.
The drawbacks? Lenco transmissions are long, noisy and they suck at downshifts but none of these are relevant because this is primarily a drag racing transmission designed to reliably transfer maximum torque and horsepower over the length of a dragstrip and it does that very very well.
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A quick story from my side: The GF wanted specific self-watering pots, a few units. In the store, they were bizarrely expensive, so I refused to get robbed like that. Then I remembered I have a 3D printer. I run linux, so any CAD software is not very straight forward. Then I remembered you advertising onshape. Gave it a try. I had no previous experience with CAD, so I watched a few of their courses, enough so that I can design a rip-off of the pots the GF wants. Printed several at 1/4 of the price that I would have paid in the store. 10/10 would recommend onshape and their courses.
*dont let the intrusive thoughts win, my bank acount cant take it"
Why are herringbone gears not used in any transmission? they are as silent as helical gears, and stay centered like straight cut gears...
@dsconnectedn3uron324 too expensive and complicated to manufacture, I think.
Can you do a follow-up video about a Gear Vendor's Overdrive?
Of course I want to watch a video about the strongest transmission ever built at four in the morning.
20:43 here, tell it to ebay!!!
Literally me
Bro... Let me eat my chips in peace without reconsidering my life choices lmaoo
@skybirby Enjoy! 🥰
Heh, saw this at 4 03 my time
couple years ago a company launched a planetary gear crank for mountain biking. It fell out of popularity due to price and weight, but I still use one and love it. instant torque application, able to shift under load with no delay. able to shift without pedaling. it's an amazing little gearbox.
Truvativ Hammerschmidt about 20 years ago? ;)
Old 3 speed bikes use a tiny planetary gearbox.
Rohloff Speedhub?
Sounds like it just needs minor adjustments to become more well accepted.
hell yeah. I still have one on my freeride bike with single speed rear. gives me a climbing gear when I need it.
I'm all geared up to watch this.
Pun not intended 😂
I don't know man..
This guy seems kinda shifty
“Boo this man!”
Pretty good joke ngl
@creamwobbly And definitely *ENGAGED*
Gear down for what?
I'm honored to be a part of your video🤪0:17
Heyy theree! Thank youu
Could this be the start of an Iconic Gearboxes series
I NEED a video on the ZF 8 speed. Such a wonder how it is in soooo many cars at such different power levels and purposes. Or are they totally different transmissions that just share the name zf8🤔
i sure hope so. i would love to get geared up
@Oncelerax Weber university channel you can thank me later when you get to the 4 part series with hour long episodes about the history of ATF
And chassis, and suspension
T56 is like hold my beer
Fun fact: stacked planetary "auxillary" boxes first appeared on haul trucks.
To have more low and more high gears the truckers would mount a 2-speed or 3-speed planetary "box" onto existing gearbox (3 or 4 speed originally)
And some drivers would mount 2 or 3 boxes.
Many trucks today have that architecture still, hence why they can have 24, 36, 52 gears. Or rather same gearset in 3,6 or 9 different ranges.
This is the same as early overdrives on cars. Was a simple planetary gearbox added to a 4 speed manual. The one on my Volvo 240 only worked on fourth gear. Corvettes used the Doug Nash 3+4 gearbox so it could get better fuel efficiency without killing the fun of classic four-on-the-floor performance when you wanted it.
@calvinnickel9995 Offroad vehicles also used a secondary planetary gearbox for a lower range and overdrive. That's why they have two gear shifters.
12:29
"when you rotate them, they rotate."
Mind. Blown.
We don't consider him a wise man for nothing!
Let's add that to the words of wisdom
“The transmission knows what gear it is in because it knows which gears it isn’t in.” ;)
IMPOSSIBRU
@noahrobin1941 The missile knows where it is at all times. It knows this because it knows where it isn't, by subtracting where it is, from where it isn't, or where it isn't, from where it is, whichever is greater, it obtains a difference, or deviation. The guidance sub-system uses deviations to generate corrective commands to drive the missile from a position where it is, to a position where it isn't, and arriving at a position where it wasn't, it now is. Consequently, the position where it is, is now the position that it wasn't, and it follows that the position where it was, is now the position that it isn't. In the event of the position that it is in is not the position that it wasn't, the system has required a variation. The variation being the difference between where the missile is, and where it wasn't. If variation is considered to be a significant factor, it too, may be corrected by the GEA. However, the missile must also know where it was. The missile guidance computance scenario works as follows: Because a variation has modified some of the information the missile has obtained, it is not sure just where it is, however it is sure where it isn't, within reason, and it knows where it was. It now subracts where it should be, from where it wasn't, or vice versa. By differentiating this from the algebraic sum og where it shouldn't be, and where it was. It is able to obtain a deviation, and a variation, which is called "air"
14:51 Portugal Craig’s list?? 😂😂
Great video, one detail though: You shouldn't count the gear contacts that are in series, it's the weakest point that matters. For the traditional transmission example you showed, it's the second gear pair (as that has larger input torque) That is a single gear pair with (depending construction) maybe 2-3 gear teeth in mesh at a time.
With planetary transmissions, you have a divided path of torque. Thus the number of gear pairs meshing is the number of planets (in above example, three)
Was looking for this comment so I don't have to write my own.
@charlsmann6188 same
@charlsmann6188 Me to😆
I saw that Lenco & others make a street able 5 spd multi lever gearbox but is it less engaging/fun to drive on the street VS a traditional manual sports car transmission?
Or is that a personal preference?
@michaelbrinks8089personal preference. I've seen some people drive standard sequential transmissions, which are similar in how you have to shift, unlike a standard H pattern in which you can skip gears.
8:01 ohhhh.... It all makes sense now
The touch of 'Murica was a beautiful addition, thanks!
3:45 that was awesome
@tucker8594 ye🎉
I agree. I had a good chuckle at that.
Everything could do with a lil' more 'Murica
Engine go brrrrrr
One more technical correction. The way you are counting the contact points does not give any information about reliability of the system. What really counts is the "number" (surface area to be more exact) of pressure points at any identical power exchange points down the chain, so you only need to add how many of them work in parallel. In first case there is ONE pressure point and in the other only THREE, not six or twelve. Those six and twelve points only contribute to 2x adn 4x power losses but not to the reduction of instantaneously acting forces and increase in reliability.
Was hoping someone pointed this out.
I would not have guessed that the reason reverse has a loud whine noise is because it uses straight cut gears vs helical. Thanks, I learned that if nothing else!
@Failure_Is_An_Option If a person like him, or myself, knows virtually nothing about gears of gear types, we simply won't have a guess because we have nothing to base our guesses on. Only reason I knew that before this video is because I had seen it in another video some years ago.
Not having a guess doesn't make us dumb, like your comment insinuates. But if in your eyes that's the case, then you are also dumb, so it's hypocritical to be snarky over this 😉
_(for example... Do YOU know which is better: an Albright or a Nail Knot? Or why?)_
I did know this, but I also first found out about straight cut racing gearboxes, and the noticed my reverse sounds very similar, and that reverse gears are also straight cut; and only after that I drew the conclusion why reverse gears sound like this.
Before that I was told that it's just a "safety feature", such that people will hear you reverse.
@sasjadv In the type of transmissions I deal with the reverse gears are not straight cut, still make the same sound though. For reference they are the Toyota T50 gearboxes.
Same why electric race cars sound whiny. Straight cut gears, only the engine roar is missing.
@JFBence Then explain why gearboxes that don't use a straight cut reverse still make the same sound?
Some of you information is extremely outdated.
I knew a transmission builder in Boise, Idaho, who built 700R4 GM transmissions to put in 2000 hp dragsters in the mid 1990s.
They lasted for literally years.
I had him upgrade one for me with 29-sprag clutch rings, 6-planetary gearsets and 2 extra clutches per pack.
I routinely pounded the wheels off that truck hunting and off-road rock crawling for 10 solid years.
It has a diesel engine, 38 inch tires, 1-ton axles, 8 inch lift, 9000 pound truck weight and after pulling full trailers routinely, the guts of that transmission were beautiful and clean and still banged into all 4 gears.
I told him I wanted it to chirp the tires when the torque converter locked up, and he gave me more than I asked for.
Had the flywheel not cracked and taken out the front pump bushing, it would have still been running all the original parts from 1996.
Very happy to see you utilizing the 3D printer for content :) .
you lowk look like him lol
I live in the US. I love the "murica" joke and adding the little supercharger.
It's pretty on brand. As God intended.
Meant to listen to this with one ear while cleaning the house. Was so riveting that I actually just sat down and paid full attention. Fascinating video!
one should not disregard the fact that pulling a gear stick backwards is much more enjoyable than pusing it foreward
The greatest advantage of planetary gearsets is that they nullify radial load, or the load trying to push the gears apart against each other. For that, only 3 planets are enough (2 makes it unstable), but putting more planets will help you with heat dissipation, stress spreading and smoothness.
Lencos are bad at downshifting because of the sprags. When you downshift a lenco, it will just freewheel, because the engine and the output shafts of previous modules will be at lower RPM than the input shafts of the modules after them. If you step on the gas to rev-match, the sprag will "dump", and it will damage them over time, as its friction area is extremely small. Fixing that demands two clutchpacks per planetary gearset, one for locking the sun against the casing and the normal one that makes it 1:1. It makes the modules heavier, but allows for exponential operation, giving you (2^[number of gearsets])-1 gears instead of [number of gearsets]+1 gears, so the weight and size of the package is still manageable.
Doesn't that sound like not exactly an advatage oflencos but of not using helical gears? If this is the biggest advantage, why aren't there classic manual transmissions without helical gears? Noise is mentioned in the video, but past certain torque that's probably a tradeoff well worth making?
Planetary gearsets only balance load on the planets, not on the sun or ring. Edit: Sorry, my comment was about axial loads, not radial. Nevermind 😊
@tompoczos8312 Yes manual boxes with straight cut gears exist for racing purposes. They are quick to recognize by their typical gear whine sound. Like a car with a manual gearbox driven in reverse (not all cars have straight cut reverse gears, but many do).
Three modules with twin clutch packs would give you seven forward ratios, which sounds like it would make a very fast, bombproof transmission for circuit racing. I wonder why nobody has tried that?
Four of those modules would give you 15 forward ratios. Not sure what that would be good for, maybe semi trucks? But cool no matter what.
@ComplicatedStuffa company (called PPG) makes a straight cut gearset for the Subaru 5 and 6 speed transmissions. They also make a set that's 1-3 as straight cut, and then 4/5/6 are normal helical gears for driving to/from the track. It's a really interesting thing that they've done
4:06 To be exact, your fingers are not exposed to net zero torque. The fact that you stopped the axle from spinning does not mean you don't excert torque and vice versa.
I've seen so many exploded diagrams/drawings of planetary gearboxes, but this is the first time I have seen a good, nay, excellent, *explanation* to go alongside. Trying to understand by just looking at a drawing is hard! And something always seems to not quite make sense.
Thank you.
Next, the Rolls Royce Power Gearbox for aero engines... 70,000 to 100,000 hp claimed. And explain what they have done to overcome the issues of the Lenco... Looks like dual helical?
Honestly, I'm not sure where else I expected the strongest transmission to come from other than the land of 3,000HP clutch dumps.
1:00 vibecession ghoul 🥀
Huh?
Vibecession is a neologism describing a disconnect between a country's economic indicators and the public's negative perception of the economy.
@aethelred9781 Vibecession is a neologism describing a disconnect between a country's economic indicators and the public's negative perception of the economy.
One thing you mentioned is using other people’s ideas to improve your own, my coworker had to explain to me that “ we stand on the shoulders of giants, if you use someone’s work to improve your own then do it”. I asked him about using his foundation to build be up for a new idea and he was excited about it and wanted me to succeed. I felt it was wrong because it wasn’t exclusively my idea but we all have become better for it teaching and collaborating together to make a better more successful team. Don’t be afraid to ask, collaborate, and innovate. Just hide it from the slackers and IP thieves.
I always called them lencos. I always figured it was a brand. But like vice grips, everyone just calls them that, because no one usually knows the actual name lol
I had no idea how they worked though, so thank you!
It is a brand...
@Karl-r5j that is quite literally what I said.
locking pliers
@kingsolomon4392i am aware...
@KwAgeeevidently reading comprehension is challenging for some😂😂😂
When D4A is roasting the affordability in the US from a thousand miles away, you know we've got issues
9:19 Technically 16 speeds, if you don't only use combinations where the levers are all pulled in order. IIRC on some military vehicles there are very complex looking diagrams on the transmission that describe the many possible lever positions and ratios.
I was thinking the same the gears are like 2^n where n is the number of modules(the two comes from module unlocked or locked)
taking it outa a race situation one could probably go back to helical gears for noise, and get real fancy with a H pattern to make a 3 module be a 8 speed manual.
@Markes12344_L That’s a great idea.
I was thinking this too, but there's also a bit of a problem in that if you tried to go through all 16 possibilities by shifting one lever at a time (eg using the grey code), inevitably the sequence of gear ratios would not be in increasing order.
The usage of a separate clutch could alleviate that sort of issue
This concept was introduced into heavy vehicle transmissions in the 1930's. It was mostly used in buses but was not manually shifted. The driver had a short stubby gears stick that was an electrical switch and it activated air cylinders that drove band clamps that grabbed the ring gear of three sets of planetary gears. They were a four speed transmission with reverse. The vehicles did not have a manual clutch, instead they had a fluid flywheel much like a torque converter. they were called Epicyclic gearboxes.
I've seen these transmissions a lot of times in my feed. This is the first time I actually understand what happens. You did an awesome job in explaining. My compliments. Thanks
I would really love a video like this about ecvt transmissions. I drive a lexus hybrid and know a good bit about it but still struggle to understand how it actually gets the torque to the road all the time. Itd also be nice to hear about their reliability from someone who knows what theyre talking about rather than people who think my car is belt driven
12:50 - Or we need Citroen and their double helical (herringbone) gears.
Double Helical has a gap between the different gear angles and Herring Bone do not. Double Helical is thus less expensive to produce but not as compact. Herring Bone can be used as a pump. Neither one has axial thrust problems.
Those must be fun and cheap to machine!
@bradhuffjr777Also something of importance; DO NOT back drive Herringbone Gears! They WILL Break and it WILL be Expensive. Oil doesn't really compress well, it'd be the equivalent of lubricating with pea gravel.
@Stormreaver1000
I have never had a problem with 100psi and less flipping the gears made from 6061 Aluminum extrusions and no heat treat. My area of experience is multi stage AKA Dry Sump in motorsports. What is your area of experience? Hard Coat Black anodizing with Teflon helps to see wear and/or scoring when servicing. Valve Spring chips are hard to find, intil they pass through the scavenge section spur gears... 🤔
Funny part is that there are machines in existence with "double chevron" gears which predate the Citroen patent.
everyday i find more appreciation for planetary gears. they are also used in ecvt hybrid transmission, smoothest transmission i ever used.
It must take a lot of work to do all the research, building 3d models, writing script, filming and editing to make one video.
Kudos for all the work you do to keep us informed 👍
9:22 underrated moment
Wellcome we are back
3:49 preciate ya bud🇺🇸🇺🇸
I may be incorrect because I'm not an engineer but if you think about it, but in order to minimize wear you want to increase the number of contact points in PARALLEL. The planetary gears have three contact points in parallel (between the sun and planets and between the planets and ring). In a manual transmission there is only 1 contact point (between the gear on the layshaft and the gear on the output shaft). Contact points in SERIES only complicate without adding durability. That means planetary gears are still 3 times more durable then manual transmission gears.
Yes, always the weakest link fails in a chain, so connection count in series should not matter in terms of durability.
Missed opportunity to talk about helicopter gear set as it uses the same principle to slow down the rotors 😂🎉
Thanks for making this video! There is shockingly little said about Lenco's out there. Even when you buy one they don't come with instructions, lol. You pretty much need to call and talk to Lenco to get the info you need like what oil to use and such. I've been drooling over these transmissions for 20 years now and I finally bought one this summer and I'm currently putting it in my car. I was familiar with how they worked already but I am super happy to see this great explanation that I can share with people!
Another advantage of the Lenco is that even if one clutch or gear breaks, you only lose your highest gear which means it's still perfectly drivable, and it's so simple and modular that you can easily and cheaply repair it in a day.
This is why you're my favorite automotive channel!
This reminds me of Red Victor One. As far as I remember that owner works as a transmission tech and decided it's a brillant idea to build a street legal 3000hp drag racer to drive around town as much as on the strip.
I sort of knew how Lenco transmissions worked, but not completely. You did a great job filling in the gaps in my understanding of a racing transmission that's fascinated me since I was a teenager watching drag racing back in the '80s.
1:04 hit me right in the feels man 😅
At this time, this is the best channel at explaining automotive mechanics. Tks from a Portuguese to someone who decided to call my country home.
Lencos!!
Great video, very informative. Lenco's used to be very popular in drag racing but regular manual gearboxes made by Liberty (twin counter shafts) have replaced them because a Lenco sucks up a lot of HP to spin. Torque convertors have become so good that Lenco's are also being replaced by TH400's, of course there is not an OEM part used on those $12k TH400's, including the case. They are regularly subject to 4,500+ HP, even over 6,000 in some cases. The guys who still run Lenco's often put a torque convertor in front of them instead of a clutch.
Unfortunately racing is becoming homogenized, once one guy finds a "winning combo" everybody else flocks to it because it's too expensive or difficult to do anything else.
Man, someone was smart enough to make that transmission. I sure ain't, but im glad someone did!
Ford Model T has a manual planetary back in 1908. And yes IT WAS USED FOR RACING... once the 2nd Model T was built!
I bet they didn't even wait that long because there were a handful of cars already built before the T 😅
@brough59 A Model T or Doble E-20 (which is a high-end steam car noted for Howard Hughes having broken 100 mph in one) would absolutely thrash a Benz Motorwagen in a race bro 😭
@lsswappedcessna i didnt say it would be a close race, and there were thousands of cars in existence before henry ford started producing any
3:13 that zip tie tail is gonna kill somebody!
My 2002 Ford Ranger XLT quakes in fear of what I wish to do now.
1:01 JIUCE PEOPLE DOING THE JOB.
No channel matches the levels of this guy ! Great teacher .
15:07 - pa, para pa, para pa, para pa, the only thing missing is the Nokia mono theme tune :D
A five speed St1200 on a high power street car is a very stupid and hopeful dream of mine
Already know this gonna be another great vid
Hi! The another factor to consider is that each gear mesh loses about 5% of power, so the transmission is least efficient in lowest gear, and most efficient in highest gear. These losses in efficiency are evident as heat. The design of the automatic transmission is such to reduce the number of gear meshes to a single mesh point for each gear speed / mesh pair. Additionally, there is the ability to lock the torque converter, which acts as a fluid clutch and provides some of the "slush" in a slushbox (auto trans).
10:48, some heavy truck manual transmissions have 3 counter shafts to handle the torque, but most OTR trucks will have 2 countershafts.
He should do a video on the Roadranger and other commercial truck transmissions. They have some neat goodies inside because of their commercial nature and lack of synchros, i.e. the transbrake that's engaged by fully depressing the clutch.
@lsswappedcessnathey're not that mechanically complex, which is a good thing, but for the most part they're just like an automotive manual transmission that's big and doesn't have synchros.
@jaredlancaster4137 I mean I don't think "regular" transmission have a high/low range and a splitter for every gear. Of course not all of them are 18 speeds but some are 8,9,10,12,13,15...and they can operate in different ways. A standard 10 speed is a 5 speed with high and low but then there was a "super 10" where you had 5 gear positions but instead of 1L/1H, 2L/2H,etc,etc you had 1st/2nd, 3rd/4th, 5th/6th, up to 10. There is a ton of variation in HD transmissions.
Those 3 countershaft macks are like rowing a boat in cement. Much slower bc of the higher inertia and no real benifit over the twin countershaft eatons.
I had a two section/three speed Lenco in our C/Dragster, a little rear engine dragster back in 1970's. It worked great with the approximately 700 horsepower engine and slider clutch. After 175 runs where we ran the engine up the 10.5K RPM and dumped the clutch, it was barely broken in. We used a CO2 operated pneumatic shifter with buttons in the steering wheel, which worked great as long as the hoses didn't leak. The main issue I had with it is that there was a lot of drag caused by the clutch packs. You couldn't turn the input shaft with your hand, no matter what gear it was in. Even so, our little car ran hard and reliably. Good transmission.
I wish you explained the virtual consequences of the said disadvantages of these Lenco transmissions like moneyshifting it, but this video is highly educational and i liked it
...and why they suck at down shifting!
@Harry_GersackClippy would never struggle downshifting
they made a destruction proof transmission, the easy way, by making it efficiency proof, put a ton of material in there and eventually it will be indestructible
😂👌
4:30 a good explanation how Toyotas “e-CVT” works.
10:53 maybe I’m wrong but I think it’s important to point out that the load is passed *through* two gearsets, but it is not *shared* by two gear sets. The gear sets are in series, so if one fails, it all fails. So in reality, the torque is being handled by 2 single gear sets independently. It’s like counting the links of a chain and thinking they each add up cumulatively in load capacity
The same can be said for the following count on the planetary gears , just because a single planetary gear has two contact points doesn’t mean the torque is shared between those two points. Its a series/parallel distinction.
I think the idea is such as for one to fail they all need to fail simultaneously. I don't think chain analogy suits. But it's just my opinion. For no.1 to fail there needs to not be a no.2 contact points.
i loved the Lenko era in McFlurry
man i love this channel, you explain 1000% better than the others
i loved the explanation of the dirt bike valve stems but this might be my second favorite episode
"Hmmmm... needs more 'Murica." 🤣 Chef's kiss
Can you please make automatic transmission video. Thanks 👍❤ love your videos ❤❤❤
The level of engineering makes me want to cry. It’s so beautiful.
the algorithm doesn't think I like cars, I guess. Never seen that before
I've seen plenty of videos of sequentials with straight cut gears and turbo 400s with manual valve bodies though lol
Not mentioned is that there is no engine braking in any ratio other than 1:1. No problem for drag racing/constantly under acceleration. When street driving, when you coast the sprags are over running, when you stab the throttle you lock the sprag very harshly which is what you will break. They’re not easy to come on/off the throttle or downshift and accelerate without hitting the sprags hard.
2 minor points
- the contact patches don't matter (adding more gears increases contact patches without increasing strength), its the number of points required to fail, in the auto its 3, in a manual its 1
- spur gears are slightly stronger as they are more efficient at pushing the gear in the desired direction, so less load on the tooth for a given output load
Nothing stops a constant mesh transmissions to have multiple gears in contact.
Not that rare either.
Also the claim that the lenco is stronger than automatics is ridiculous too.
If sprag clutches is the strongest or not is debatable, but there are autos that uses both and i would say that hydralics are pretty good at applying force.
I came from watching an 38.6 pound of steak, brainrot memes and sea fishing videos but thanks to the algorithm, I'm here
3:47 okay this was hilarious 😂
8:50 what if you made this kind of transmission out of locking hydraulic torque converters in series instead of torque converters? it might be even stronger because you can't break the gear teeth off a fully hydraulic system
The whole point is that fully mechanical systems are super easy to work on. Can simply disassemble and reassemble, no pressurized systems to drain and fill and filter
that would be horribly inefficient
Gm made a transmission like that in the 40s and 50s. It was called the dyna flow. It used a variable 5 element torque converter and was very slow.
Best anti-theft device ever designed.
Knew someone years ago that had a lanco automatic in a 55 Chevy, it had a 2500 psi co2 bottle in the boot to actuate the shift, ran 7.2 1/4 mile.
Love to see you do the insides of a road ranger transmission, herringbone gears to stop end thrust and twin lay shafts to increase contact points. Had one do 1.3 million kilometres pulling up to 90,000 kg without a rebuild.
Are you sure they didn’t run a Powerglide? That only has one shift point, and it is common to use a CO2 solenoid on the shifter to push the lever from 1st to 2nd. And it is called a «Lenco» with an E. 😁
I'm not a fan of Eaton's automatics/automated manuals (they shift slow as dogwater in my experience driving a newer Kenworth T680) but all of the roadrangers are very good. I'd love to get a deuce and a half and swap one in alongside an older diesel engine like an 8V71 Detroit. Just thinking about them reminds me of doing my CDL road exam a few months ago and floating a downshift in front of the state trooper who was doing the test. In my state floating gears is an automatic fail on the road test for whatever reason, even though 99% of truckers who drive stick for their job do it (unfortunately I drive an automatic truck, but fortunately I moved into a Volvo a few weeks ago so it's the decently cromulent I-Shift) but he didn't say a thing.
@sjokomelkdefinitely lenco, was a supercharged outlaw, tune up crew flown out from the states to Australia, not a typical build.
Ps I driver better than I spell.
Hate the autos as well, spent 23 years teaching road ranger, don't care what anyone says about new safety features, learning with a road ranger makes the best drivers.
@davidreeves2911 That last typo made it so much better 🤣
I so want this in my 1.0 car for absolutely no reason, just because it's cool
Yea Im pretty much salivating at the prospect of a regular planetary gearbox video........ would love to see the evolution from the lowly 2 speed to the current standard 8-10 speed
This channel is incredible to the point of disbelief.... thanks as always D4A
There's nothing lowly about the 2 speed except your gas mileage when using one. They were some of the most reliable traditional automatic transmissions ever built and still heavily utilized in drag racing for people who don't want to drop 8 bands on a Lenco.
I've seen Lenco just in vids of cams inside dragsters, ut had no idea how amazing they are!! THANK YOU D4A !!!! YOU RAWK!!!
Am I right by saying that you can engage these locks in any order? So you actually get more ratios than stages? For example from 1:3+1:5+1:7 stages (theoretical values) you can also get 1:21 ratio?
Correct
There is a downside of doing this?
@fl4v10filho just rpm drop depending on the ratio lever you shift
3:45 "Needs more 'murica" 😭
1:55 I believe you still need a clutch to get it moving
Tbf you still need a clutch to get a sequential going too
'Need' is a strong word. If you're clutch is f'd and you don't have a neutral safety switch, key-starting (engine off, trans in 1st or 2nd, engage ignition switch / turn the key) will get you moving from a standstill just fine.
Ya you do need one for take off but after that it's pedal to floor and grab gears
They also make a torque converter style. Bruno/Lenco.
Pretty sure that's what he meant by "You just take off the clutch" Just used the wrong words on accident.
THANK YOU ive always wondered why lencos were so good
I've only watched a few of you videos, but again you take a concept and present all the pertinent information in a simple visual and verbal way that is simply understandable. Thanks for sharing!
Tnxs for this clear explanation of this lenco!
Fun fact about Lenco transmissions is that they can use either a clutch or a torque converter.
One thing to note about the strength of a planetary gear set is that the separation force of the gears is contained by the ring gear. So there are no forces trying to separate the shafts like there would be in a conventional manual trans. When big torque and shock loading is involved these forces lead to broken bearings and cases. Semi-truck transmissions use dual counter shafts to handle these forces.
The twin or triple countershafts are for the additional gear sets. That's how you get 15 speeds in a truck transmission
Great! I finally understand how planetary gearbox works
Can you really say there are that many contact points if they are inline to each other? You can add a bunch of 1:1 gears to a manual, but it doesn't make it any stronger. The weakest one in the chain is the weak point.
However I can see how it has mutiple sets of 3 contact points in parallel, where a manual only has 1 point between gears.
Thank you, looking for this comment
You're right, only the weakest link counts. The advantage of planetary gearsets is that it nullifies radial load, or the load trying to push the gears apart against each other. For that, only 3 planets are enough (2 makes it unstable), but putting more planets will help you with heat dissipation, force spreading and smoothness.
Correct - the advantage is only in parallel power transmission paths, so with three planet gears per set the advantage is a factor of three, not six; the conventional countershaft transmission shown has only a single contact per gearset.
@gsilva220 tbh it was probably a psyop to get more comments.
The fact that I have seen this exact video says alot
11:17 you dont need to break all the points but only 3 and in regular manual only 1 contact point
I own a Lenco, nice to see a video introducing it to the masses
Very interesting, I'd like you to put out a video on the Model T Ford transmission. Keep the great work.
That would be scary...
My 50 year old lawn tractor has a planetary transaxle, I think it will make to 100 without failing. Gravely, built to last!
love bosnia from bosnia
These *metal* *gears* do seem pretty *solid*
You implied, but didn't state explicitly, that OnShape works on Linux. I can confirm that OnShape is accessible to computers using Linux based operating systems. However, smartphones and tablets are still a no-go due to the lack of a mouse.
Well explained, very interesting video. Just one small error, when you talk about the strength the number of contact points in series does not really matter, it is always the weakest link that will break, which would be where you have 3 contact points, since all the torque is going through those 3 points. Thanks for the video.
4 module lenco and a 4 rotor rotory motor seems like a fitting scenario
Sir this is some 100% proper education.
Don't forget, started with older tractors.