1 Way - 2 Way - 1.5 Way LSD - Explained

[@andrewfossatti4937]

Already been subscribed to your channel for several years. Why am I only finding this video now in 2024?!

[@EngineeringExplained]

Finally, I agree that the end of my video was a little rough. I need to start watching them more thoroughly, and redoing parts where I screw up. I do usually require more than one take, and sometimes split them up. I guess this time I just didn't realize that I was straying off and blabbering. The intention of my video is for it to sound conversational, like you're in the room with me and I'm teaching you (no cameras around). Thank you for pointing out the error at the end.

[@datsuntoyy]

WOW, you've gotten a lot more refined and eloquent since then.

[@15thelongway]

Those voice cracks were savage

[@philogre5771]

Come a long way for sure 👍 thank you for your explanations

[@datsuntoyy]

@@timtwing5886 Sure thing mr negative. "gotten" is an accepted term as past tense of got.

[@EngineeringExplained]

If you're going around a corner while braking, a 1.5 way may be better, so that your tires still transfer some torque, but also allow for different wheel speeds so that one tire is not dragging or skipping. Of course, with ABS for all 4 wheels, applying the maximum braking force doesn't require a tricky differential. Since ABS is banned in nearly all forms of racing, these differentials can provide benefit.

[@EngineeringExplained]

What I was trying to say is that it reduces the force that "locks" the differential together than if it were to be a 2 way LSD. Having a 1.5 or 2.0 way reduces the likelihood of one tire from stopping than a 1 way, but they way I said this was basically unclear and wrong. Basically if you're braking in a straight line with no ABS, having a 2 way diff would be ideal if conditions were different for each tire.

[@fry863]

Just about every time I have a question on how something works you have a video answering. Thanks for doing what you do.

[@EngineeringExplained]

I work for a forklift company in Oregon. Check out my FAQs for a complete answer to your second question. The FAQS are on my website, link is in the description. Cheers!

[@tombax338]

Watched all of the related videos today, and I learned a lot. Thanks for these informative videos, much appreciated!

[@EngineeringExplained]

Very welcome, thanks for watching!

[@kevinlaracaminero5493]

tombax338 same

[@EngineeringExplained]

When you brake the rear tires, you slow down the drivetrain, starting at the wheels, which are connected to the drive axles and thus the differential. By braking the tires, this force does pass along to the differential. A clutch, torque converter, system of clutches in an auto box, etc... is the link where the engine and wheels are no longer connected. So to slow your car down, you also must slow down rotating components such as the driveshafts, transmission gears, and diff gears.

[@steveskouson9620]

I saw LSD, and was taken back to the '60s. But, you're talking about something COMPLETELY different. Like, in Star Trek 4, Kirk mentioned getting involved in LDS. I had no idea, Kirk was a Mormon. steve

[@EngineeringExplained]

Correct, it can allow for the tires to rotate at differing speeds, depending on how much lock-up you allow the differential to have.

[@EngineeringExplained]

You are very welcome! Thanks for watching

[@EngineeringExplained]

Preload is exactly that, the load on the clutch pack prior to any other forces; it's constantly applied so there is a set amount of torque transfer. The percent lock refers to how much torque can transfer to the wheel with more traction. For example, a 75% lock means the tire with more traction can receive 75% of the torque going to the tire with less grip. If anyone disagrees or knows more, please share.

[@EngineeringExplained]

Thanks, glad to hear that they're clear for you.

[@XHikotheproX]

I never leave one of your videos not understanding something. I always go "this makes complete sense" before this i really didn't know anything about LDS's, its one of the few major automotive concepts i could say that about. Great vid, as always!

[@EngineeringExplained]

So that both rear tires can spin rather than just one while in a drift. If it were an open differential, what would likely happen is the tire with less grip would spin, and the other would remain with grip, basically preventing you from drifting. A locked diff ensures that both tires are always spinning at the same rate, so this can also be used in drifting.

[@EngineeringExplained]

Yes, aiding in decelerating so that the tire with more traction can slow the car proportionally greater.

[@EngineeringExplained]

Yes, this does seem logical. I'm finding mixed messages after further review. On one hand: "Depending on the initial torque you have the diff set up, this diff will be locked when you are both on the gas, and on the brakes." On the other: "the differential will provide some level of limiting under engine braking." Regardless it seems engine braking is required. I'm unclear on if braking enhances this.

[@Dan-TheOracle]

"While in neutral and decelerating, the differential will act as an open differential, regardless if it is a 1 way, 1.5 way, or 2 way LSD." that is still actually quite wrong. when freewheeling it still acts as an LSD but a non mechanical type. with the car off the ground you should still not be able to turn one wheel independent of the other (or at the very lest there should be some resistance) because of the preload on the clutch packs while at rest so how much LSD effect there is when your freewheeling will depend on this preload. apart from that small glitch, great vid explaining the differences and how they work.

[@EngineeringExplained]

Just checked out OS-Giken's website. Looks like they have all 3 types? I'd check out the product manual for your specific model.

[@EngineeringExplained]

This does makes sense. It does seem you would have to have a drivetrain connection (engine braking) causing the pin to lock the diff together. Reading up more on it now.

[@EngineeringExplained]

It's not locked when you are not accelerating or decelerating. It's like an open diff then, so going around a corner with your foot off the gas allows for the tires to rotate at different speeds.

[@EngineeringExplained]

Well one thing that was always a big help for me was to simply go to a junkyard and mess around with engines. One of the easiest (and cheapest) ways to learn, at no risk of damaging your own vehicle.

[@Limeayy]

i thank jason fenske for teaching me how they work. i didn't 100% understand how the clutchpacks squeezed together. i thought they squeezed together and locks up due to just the rotation of the differential causing it but i was kinda thinking about like... a how'd i understand from the A to D. Doesn't 100% make sense. This make alot of sense, the pinion shaft is letter B and the pressure ring is the letter C in essence, with D being differential lockup/clutchpack being squeezed together. Thank you again Jason.

[@EngineeringExplained]

Unfortunately that's just a bit too specific. I'm trying to teach concepts and ideas so that they can be applied to more specific applications, such as your example.

[@EngineeringExplained]

I don't believe it acts as open unless you are in neutral while you brake. If in gear, and braking, there will be a locking force from the engine.

[@ryansterling4226]

What about Helical Gear limited slip differentials that are: 1 way, 1.5 way, and 2 way. And their effect in a front wheel drive car. I know you did the videos about the 1, 1.5 & 2 way clutched type of limited slip differentials, and the Torsen limited slip differentials, but those are not entirely the same as 1 way helical, 1.5 way helical and 2 way helical differentials. So basically, how this video explains the clutched 1, 1.5 & 2 way LSD, would you be able to make a comparable video about Helical geared 1, 1.5 & 2 way LSD's? And, could you help shed some light on their effects in a front wheel drive car? Thank you for all the wonderfully informative and interesting videos and explanations you have made, I truly have learned quite a lot from you and greatly appreciate your expertise and awesome way of explaining things in a manner that makes sense!

[@EngineeringExplained]

Clutch type LSDs are a common forms of LSD. Simply google "clutch type limited slip differential" and you'll have a bunch of different manufacturers pop up.

[@turboluvr5404]

I'm glad the whole braking forces point was raised. Great explanation overall. This diff is probably meant for a vehicle running on a road course using a manual transmission, then some of the reverse torque characteristics would apply. Also, I know this is the 1, 1.5, 2 way video, but there is a more basic LSD design without the crosspin ramp for the 2 way. These are the most common LSDs and just use the side gear separation forces. They are a little easyer to understand.

[@Skyhawk656]

You sir, need to go into teaching this stuff. I learned a LOT from this.

[@EngineeringExplained]

Eventually, hopefully, yes, haha. Thanks for subscribing!

[@EngineeringExplained]

I think you're over-complicating it a bit. The locking starts when there is a force accelerating (or decelerating for 1.5 and 2 way diffs) the differential, regardless of what the wheels speeds are.

[@iKRPictures]

you're the best dude, thanks for all the information

[@rhubarbpie2027]

WHAT A TIME CAPSULE

[@EngineeringExplained]

VLSD, then Torsen I believe.

[@EngineeringExplained]

You're welcome!

[@bitelaserkhalif]

Hey Engineering Explained, have you gotten any monetization problem with this video?

[@0Sirk0]

great vid, completely understood the concept within the first minute and third

[@EngineeringExplained]

Thanks!

[@EngineeringExplained]

Correct, it would have to be in gear.

[@colonelclusterfuck99]

I have a question about the lockup created by the differential during braking. How does engine braking occur when you go off the throttle for too long? Also is the amount lock in the differential caused by how much you are accelerating? As always awesome videos.

[@EngineeringExplained]

Just as much so as in any other car, yes.

[@EngineeringExplained]

Thanks, they just keep going!

[@Diegothemexican13]

Jason is a national treasure.

[@EngineeringExplained]

VLSD tomorrow, cheers!

[@EngineeringExplained]

you're very welcome!

[@mikegillean]

Please make a video on which differential has best reliability for standard street use and can you differentiate which limited slip would best be used for different driving styles

[@inorbit64]

OS Giken for the Lotus elise is a clutch type differential. With a twist though. Extra springs draw the ramp pieces together, causing smoother locking.

[@inorbit64]

This type of setup is mostly used on 911 and other MR cars in order to make the car less tricky and more stable under decel. 1 way is a setup mostly used for FWD cars where decel lock will only cause understeer during braking.

[@inorbit64]

Experience tells us that momentum from the grip of the wheels also causes e certain amount of lock, but most of it is down to the engine indeed. With a 2 way in gear (depending on clutchdumps or flywheel aggressiveness) you will definately have lock during decel/braking. This will enhance stability for the car.

[@staygolden84]

Thank you for these videos man I'm learning greatly.. God bless you

[@Fifress]

So LSD locking up whilst decel will help slowing the car down? I can't really understand why it locks the diff on a decel stage, other than aiding the car to slow down faster. Thanks :) Great video/lessons!

[@eXistenZNL]

Great! I guess the next video is explaining a torsen diff? Either way, keep up the good work!

[@sephiroth1386]

The next topic should be how driver controlled differentials work. Like center ones on AWDs or the types used in F1

[@otavioamaral3599]

Hi Man, my name is Otávio and i'm particite for team SAE Fórmula Cefast in transmission system. I have a question, you tell in one commentary: "For example, a 75% lock means the tire with more traction can receive 75% of the torque going to the tire with less grip." This is True? I always thought total torque they were 75% for left and 25% for right for example. And in Drexler case you definided the best angle and type ? 30 ° = 85,272 % ca 40 ° = 58,672 % ca 45 ° = 49,231 % ca 50 ° = 41,310 % ca 60 ° = 28,424 % ca In my opinion for test in line use 45 °(1 type) for equal torques and the desaceleration angle not harm, because it generates the angle 60 ° with the torque 28,424 % different. For the other tests like skidpad, auto-x and endurance i would use 40 °(1.5 type), because in a curve there is a difference of torque and as you say. "If you're going around a corner while braking, a 1.5 way may be better, so that your tires still transfer some torque, but also allow for different wheel speeds so that one tire is not dragging or skipping." Thank you for attencion and let´s talk about, that's very interesting in engineering.

[@EngineeringExplained]

Basically you take an open differential, heat up (weld) all of the ring gears/spider gears inside until they all melt together, and you know have a locked differential. Why spend money when you could just use fire, right? Haha I don't recommend it if you plan on driving the vehicle on the road.

[@StudentDriverBR]

Amazing video, but how much is the diference on speed necessary to lock? Its like if get 10% of difference on each wheeal it locks? You can change when it lock to need more or less difference before lock?

[@EngineeringExplained]

Nope, no acid tripping here. But there's always the suggestions page...

[@EngineeringExplained]

Just trying to do my part as a public servant.

[@DifRential]

Mate, awesome videos, is there something you didn't cover??? Perhaps air lockers?

[@olafschermann1592]

Do these clutches wear out? They are slipping slightly on every acceleration when not driving strait.

[@EngineeringExplained]

Thanks!

[@kirklockwood6264]

Instead of "decelerating" it is actually "braking" that effects the AXLE not the differential which allows for both wheels to lock for hard braking and when accelerating the outside wheel just has to overcome the brake force on opposite side as a standard diff since the brake force is on the Axles clutch plates that can still slip separate from the pinion gear in diff- (unlike the standard diff or locking diff) this way the clutches (under pressure both or individually) is best for both conditions and racing as your torque is not lost (During braking or acceleration as the slipping discs limits one axle to turn more and the other to still brake or spin less "slip less" round a corner or the S's under brake or power conditions at 100% torque.)

[@posernotricer]

i actually now understand how it works... thanks

[@BMWgab]

great video, man! I've a question: does the locking starts when the angular speed between the wheels exceeds a certain difference, so there will be an axial thrust on one side? or it will lock also in straight trajectory and in normal cornering? finally, in decelerating, if i'm braking so hard in a corner, if i've a locking of the internal wheel, the external one will be locked also, right? (in this way I reduce the yaw motion about z axis). Thanks.

[@jeremysabatino5670]

This may be a stupid question but when you have limited slip differential which tire would be the main drive tire?

[@connorboll1442]

Phenomenal explanation!!

[@richardgaufo2624]

Greetings from the Philippines... you're awesome

[@Claytons91]

Why? I have a welded diff and its my daily, I have no problems other than tire wear, and it mad fun for drifting.

[@lfadventurer500]

I've seen most of your videos and find them quite fascinating.But,could you do an explanation on an LS6 Engine in a Chevrolet Chevelle SS454?

[@tafaragadze6432]

Another thing related to my previous point... wouldn't a 1 way differential do the trick, but working in an inverted manner?EG. when breaking there is more lockup in the pinion shaft and when accelerating there is less than in breaking... but there is still lockup.Does such a differential exist?

[@BMWgab]

ok, I understand; but in cornering at low speed and/or in adherence, the external wheel is allowed to have an higher speed? otherwise, don't I feel a bad behavior on the steer like in a kart or in a full locked diff?

[@panniepheng8275]

Is it good to have a 2 way kazz differential? I have a car that its stated "kazz 2way diff. very tight similar to lock but more ideal for grip also" Is it good to have, Cheers bro

[@joeynachanphasuk7002]

Pannie Pheng what car u have it on?

[@danecurrie]

Nice vids, been watching the entire diff series. Do you think it feasible to modify the pressure rings on a 1-way? Potentially welding material, then shaping it to mimic the pressure ring profile of a 2-way? Could you speak to the strength required, material used and possibly the material weakening from heat exposure? Thx.

[@danecurrie]

Upon closer investigation of your diagrams, it appears by simply machining away the linear plane on the pressure ring, one could turn a 1-way to a 2-way, thoughts?

[@tafaragadze6432]

im learning a lot form your videos. but I am only unsure of one thing. in most motorsports cars are required to yes break when going into a corner... but are also required to also accelerate at the apex of the corner and I don't think any of the clutches explained and showcased in your videos would be able d do it. could you please clear hat up for me so I can get a full understanding.

[@lordofwar1441]

would a 1 way lsd not lock up in reverse? like if you are stuck in a ditch and need to back out, you won't have the lsd helping?

[@jarrusjenkins]

so.... let me get this right, and lsd sends the engines torque to the wheel with the most amount of available traction and when traction is completely broken it locks up so both wheels get equal amounts of torque?

[@jasaircraft]

I know this guy insisting that a 2.0 will lock harder during aceleration than a 1.5 during aceleration is this correct? I thought how hard they lock depends on the thickness of the shims.

[@AaronDurr]

A scary ghost sound lol

[@JanezMeden]

Actually, if you slam on the brakes, the diff acts the same as when accelerating, because when you brake, you're slowing down the wheels, not the engine. Where the difference comes in, is the moment when you decelerate with the engine, by changing into lower gear, or just taking foot off the gas pedal. I imagine it works that way, correct me if I'm missing something...

[@dylanldelisi144]

***** the 2-way can be thought of as a welded diff when you are in a straight line but when you turn the outside wheel will slip the clutch on that side because it has to move faster than the inside wheel, i think.

[@nickamarit]

***** so turning-in using a 2.0 in a car with ABS is better when the brakes are slammed than when no brakes are applied??? interesting... and very drifty!!!

[@killer2600]

***** Close but you have to figure in the deceleration of the engine, if the engine opposed deceleration you'd be spot on but when you take your foot off the gas and hit the brake both the car and engine are slowing down so the wheels may be applying a decel force to the engine or it may not. As far as differentials go however, when braking (with brake pedal) it's a moot point because the brakes are applying stopping force to both wheels.

[@bibertkirk]

These are great videos. Thanks!

[@Stimm002]

A 1 way diff is better for front wheel drive cars, as 2 way diffs tend to cause more understeer in front wheel drive cars.

[@HazardGraphy]

would you mind to explain more on ther type of LSD such as viscous LSD? anyway, great video... thanx!

[@myrddinbataille3789]

watching this the night before my exam.

[@TheAj108]

I know this is dependent on the materials used, but how much heat is generated between the Pressure Rings and the Pinon Shaft? I am just curious to see how much it would heat up. Is there any possible way to reduce this generation of heat, besides using different materials?

[@pratikkadam300]

In clutch type LSD, TBR is not defined ? please explain about when it will work as locked differential....

[@swayingGrass]

So at 1.5, only engine braking can make the differential locked when decelerating?

[@shortfuse1993]

so would an example of a one way LSD be the Eaton posi-trac system that GM used way back in the day? and when it comes to modern cars such as lets say the Camaro, Corvette, Mustang etc etc what kind of LSD would they run?

[@Ricardo95Santos]

I have some doubts, imagine a front wheel drive car with LSD in a corner, if you accelerate the speed in both wheels will be diferent? or they to be pushed both as same speed? :s i mean, will the inside tyre push harder because it's slower? Forcing the car to "turn more"? I probably can't explain my self, i hope can help me :) thanks

[@EngineeringExplained]

I'm trying to gain a new audience :)

[@iradickerson4960]

I have a 1995 F150 4x4 with rear ABS, 8.8 355 rear differential. I Want to change it to stock Ford 8.8 355 limited slip differential.Do the 1-way apply to a ford Differential?

[@bernardandries]

Man you should be my teacher in school.

[@bassmetalheadbang]

Great explanation!

[@giles1358]

when turning a corner, one would usually brake before the corner, and apply power while turning or after the apex (but still while there is a corner). this application of power would lock the diff up thus making it understeer on the exit of the corner? YOUR VIDEOS ARE ACE, THANKS LOADS, but i have loads of questions. I hope you're still on here so you can answer them.

[@JustAlanIsCool]

With a fwd vehicle, I would say you're correct. On a rwd vehicle, a lockup scenario could engage the car in oversteer, if the vehicle has the necessary power to break the rear tires free.

[@Dan-TheOracle]

+Giles Braid "thus making it understeer on the exit of the corner?" all depends on the car and how its set up but generally your partly correct tho usually when your hard cornering with an open diff you are supplying more power to the wheel with the least grip thus getting wheelspin on the inside tyre. with an LSD (or locker) you are applying more power to the inside wheel with more grip thus propelling you faster around the corner. that being said, from a standing start with little grip (like doing a right hand turn unto a side street on a road covered with gravel) you will certainly tend to travel in a straight line and understeer as has happened to me in the past with mine. this is for rear wheel drive cars on FWD cars with lsd/lockers they do tend to understeer a lot but once you get used to driving them you can use this to your advantage.

[@mdfahim9513]

how/why does the pinion shaft moves back due to acceleration or deceleration? Is it inertia? @ Engineering Explained

[@jarekluiken7848]

So from the description I'm getting that if I have to brake on an icy turn I want to do it in neutral?

[@rombierto]

I have an OS-Giken Superlock LSD in my Lotus Elise,,,,it has 12 locking plates, which are progressive and "fully locking" What category LDS does this fall into? -Robert

[@MK3504]

I have a question, I was considering getting an aftermarket LSD for my daily driver. I was considering the 1.5 Way, but I am told that it is "dangerous to drive" and not recommended for the street in the rain,and snow, etc. By the way my car is a RWD car @ (2750lbs.) Will it effect my daily driving tremendously?

[@niipheus]

Can you explain to me what is preload and percentage of locking in the LSD? Thanks.

[@schrauberwolli]

you are awesome! thank you for sharing your amazing knowledge!!

[@wrxsamo]

Thinking about getting a car and it has the 2 way diff and it makes a clicking noise is that ok