With one wheel on the ground, there is torque going from the ring gear to the wheel on the ground because there is resistance to twisting force (torque). The wheel in the air simply spins (at the same speed). It takes basically no torque to spin the wheel in the air because there is no resistance, so there's no torque going to that wheel.

Again, one side gets 100%, and the other 0%.

One side has resistance to twisting force (torque), the other has no resistance to twisting force, and the ring gear is the dividing point between the 2 sides.

I don't know if I can explain it any different. I've tried different ways, gave you an analogy, gave you 2 links. I'm tired of explaining.

Personally, I haven't seen any manufacturer website or ad say that a locker gives 50/50 torque split all the time (a locker only does this when there's even traction on both wheels). That's not to say a manufacturer hasn't said this, but I've never seen it.

It is possible that someone selling differentials could tell you this. I have ran across salesmen that didn't seem to be very technical minded with such things, and have seen technically inaccurate information on dealer websites.

But all they want to do is sell you a locker, so they don't really care if you fully understand.

 

Aparantly i don't. I thought i did, but aparantly it is argueing with fact.

I always thought that a spool effectively "welded" your diff, such that your axles always turn at the same rate, and split driveshaft torque equally between the wheels.

This is not the case anymore, as now a spool chooses which wheel gets the torque. And it chooses opositely than an open diff.

I'll just have to keep on believing the lies and ignorantly believe my locker manufacturer.

I agree, you are saying exactly what was posted in your links, but neither the links nor your explination make sense to me. You still have not explained how the locker "knows" which wheel is on the ground, and therefore which wheel to give power to. Also, your finger analogy makes sense, but doesn't make sense in terms of the car.

If my wheels are in the air, if i put the truck on jackstands, for example, this means my engine has no torque right? but i can still turn my wheels. So what, then, is the force turning my wheels?

 

Alright then, forget it. I don't really care that much, just trying to understand a bit better. Thanks for the attitude though.

 

ike...i think youre missing the key point here.

there is virtually no torque applied to a wheel unless there is resistance to that wheel. of course, resistance to a wheel is what gives it traction. resistance to the axlesaft is NEEDED in order for torque to be APPLIED to it.

that being said, an open diff applies torque to the wheel with the LEAST resistance. locked diffs applies torque to the wheel with MOST resistance. if ones on the ground and ones in the air, the grounded one has MOST resistance and the one in the air has LEAST resistance. thus, in an open diff situation, the one in the air is spinning wildly.

yes spools are effectively welded diffs. in a diff, its the spider gears that turn the axleshafts...NOT the ring gear. these spider gears are driven by the pinion gear, which is driven by the carrier, which is affixed to the ring gear and rotates with it. in a spooled setup, there is no carrier, no pinion, no spider gears. essentially, the ring gear is directly affixed to the axleshafts therefore offering no differentiation. compare a pic between a regular diff with a carrier, and a spool.

this is what i mean when open has two shafts (that have differentiation) and a spooled diff has one shaft (since there is no carrier/spider/pinion) where the two wheels spin at the same time...even though there are two shafts.

to apply the finger analogy to an axle shaft, imagine that when youre not holding the finger in place, that is essentially the axle/wheel that is up in the air. your wrist spins it easily..right? that means no torque is being applied to spin it. now when you hold that finger in place, that is the alxe/wheel that is on the ground...and it takes force aka torque to twist that finger. so in a locked situation, one wheel in the air gets no torque since its attached to the locked axle, but is just along for a ride since its spinning..

 

The engine produces torque, which is multiplied by the transmission gears, transfer case gears (in low range), and the ring/pinion gear (total torque).

It does take a very small amount of torque to overcome rotating mass to start a wheel to turning, or to accelerate a wheel, but basically no torque to keep the wheels turning. Since this very small amount is almost zero (because there's almost no resistance to the turning), for all practical purposes it is zero.

But don't grab one wheel and try to stop it. Then your body will be resisting the rotation, suddenly creating torque, and it will take a certain amount of that torque (going only to that wheel, since the other is still spinning free) to fling your body.

By the way, I'm talking about torque split or transfer and not total torque. The 100% going to one wheel can be the total torque, but usually isn't because the wheel will usually lose traction or propel the vehicle before maximum torque levels are reached.

Just to help you inderstand, take a torque wrench and put a socket on it. If you turn the socket without the socket turning anything, the torque wrench will measure no torque. It can't measure the infinitismal amount needed to turn the socket, but the socket still turns. But put the socket on a tightened bolt, and the torque measurement will increase until the bolt turns. Then imagine the socket being a tire, and the bolt being the ground it sits on.

One thing I thought of, ever wonder why, when an axleshaft twists in two off road, only one side usually fails and not the other? Because only one side recieved enough torque to make it fail, and the other side didn't (unless it was already weakened). That's not 50/50.

 

I understand how the diff works and how it is set up: i've built both of my diffs.

I guess i'm just confused. Not really a big deal.

 

True, it's not a big deal and it's understandable. I never meant to offend anyone with this discussion, I just want them to understand, and it started with me wanting them to understand how a locker could possibly cause an axle shaft to twist in two.

 

educating, just read allll that, but i immediatly got the point in some of the first posts, although both the analogies made it that much easier to understand...

 

if you can't afford selectable lockers, run lunchboxes front and rear. i do, and so do many others. you can't beat having true 4WD off road. on road, sure the rear locker gives your rig different driving characteristics... so you learn to drive with a locked rear. as for the front, you should never run one with automatic hubs or drive flanges in the front. it makes no sense. not saying you're guarateed to break stuff, but you're just creating problems for yourself when you don't have to. you need to be looking into manual hubs way before you even look into a locked front...

 

This thread is a little off track...

For me, I try to visualize how I could possibly brake an axle shaft on the wheel that has zero traction. I imagine climbing an obstacle, one tire grabbing, other not. I can see how all the torque is going to go to the grounded tire, and that axle could fail.

Looking at it this way, I don't believe anyone could see the zero traction side axle failing first... thus the understanding of where torque is applied to the axles in regards to a locker becomes apparent.

 

To answer the original question. I think having an ARB up front would be the ultimate but my wallet won't allow it. This weekend I'll be putting my lockright axle in the front. Thanks Rob (aka Hotwheels) for the setup. I also have a Lockright to install in the back.

Rob mentioned that he put a switch in the cab attached to the wiring that exits the transfer case to operate the ADD system. If you have ADD then hitting this switch should disconnect the ADD sleeve in the axle thus allowing good turning, essentially 3WD. Or is that 4x3? At any rate, I searched and couldn't find info on this mod so I'll post my results once I'm locked front and rear and have the switch working.

So I agree - selectable up front is the best, auto locker is next, and don't spend money on a limited slip as it will let you down when the nose is burried in dirt or you are halfway up that steep trail.

 

I have to tell you guys, if I am ever required to teach someone Newton's 3rd law of motion, (every action there is a reaction...) I'm printing up this thread. It was a great read.

I can only add that I had Trutracs front and rear at one time and they kicked butt on snow covered roads. They did not do so well on rocks and I would not recommend them for that. The front was fine from a steering standpoint, no steering issues wet, dry, or icy. I just had the front tire in the air so much it didn't do a whole lot for me on the trail. I broke the rear using the e-brake to lock it up along with almost tearing off a spring perch and twisting the axle housing. BTW, they will lock up with brake biasing.

Frank

 

How does a wheel spin without torque?

Lockers make both wheels spin when locked.

LSD makes both wheels spin some of the time.

Open diffs make corners easy.

I have NEVER heard motive force and rotational inertia when discussing lockers before. I am pretty sure we need to get this to Pirate.

How many people who have posted in this thread actually have lockers? How about the good samaritans?

 

I vote that it was 69/29 as that one is different from the others.

 

Well, looking at some of the posts it appears that at least some understand. I hope you will understand too.

I don't know what you mean about Good Samaritans, but although the factory locker in my Tacoma is my first selectable locker, it isn't my first locker. I've had 2 Lock Rights, 2 No Slips, one short lived EZ Locker, and I also had one Dana Trac Lock limited slip, and one Ford Traction Lok limited slip.

Plus, from '85 to '95 while I was a reservist in the Air National Guard, I drove Chevy pickups with the weak 6.2 diesel and rear Detroit, and I've driven several Chevy trucks at my last job with the wheelspin activated factory locker (I think it's called Gov Lock), and at least one Ford with Traction Lok at my last job. And there's the 2wd Club Car utility vehicles at my current job with the cable actuated rear locker.

So I've either owned or driven several different vehicles with different types and brands of lockers, and 2 different brands of limited slip and I've experimented with every type of locker or limited slip I've driven (some many times), and open diffs too.

Keep in mind that you asked how many of us have lockers, and I answered your question in detail...

Even though the trucks in my guard unit and at my last job weren't mine, I still did some experimenting just like I've done with my own vehicles. I'll actually spin the tires on dirt, climb dirt mounds with one front tire while trying to unload the opposite rear tire, floor the gas pedal with one rear tire on grass and the other on pavement, etc., just to see what happens, and then get out and check the marks made by the tires to help visualize and understand what happened.

Fortunately, while doing all of this experimenting, the only failure while experimenting has been with a wheelspin actuated locker in a Chevy 3/4 ton at my old job. It wouldn't lock anymore after I tried to climb a mound of dirt with one wheel off the ground several times (would just make loud noises while trying to lock like the locking mechanism was stripped or broke), but somehow it drove just fine under normal circumstances.

I'm saying all of this to make a point, not to brag. I experiment, I look at the results, I feel what happens to the vehicle while trying different things, and I tend to experiment way more than most people.

Most people are just satisfied to drive a vehicle from point "A" to point "B" regardless of what equipment it has. I gotta take the vehicle and see what it can do and what it can't. I gotta know it's limits. I gotta know how mechanical stuff works, which is partly why I scored a 99 on the mechanical portion of the military ASVAB aptitude test before I went in the Air National Guard.

This helps me learn alot. I don't know everything and I'm not always right, but you won't see me arguing passionately like I did here unless I know I'm right, or at least have a very good reason for believing I'm right. And then there's the 2 links that agreed with me, so it's not just in my head.

I know it's not easy to do, but sometimes you have to accept something you don't fully understand.

 

I don't understand why someone decided to spell it "TOYODA" on my brake resevoir cover. But, I've learned to accept it. Well, almost cherish it.

Understanding and caring go hand in hand.

 

Deathrunner, I've also TOYODA in some parts of the steering. I read some time ago that the original name of the make was TOYODA but a oracle said the family to change the name because (s)he had some bad visions hehe

David

 

How does a wheel spin without torque?

Sharing is caring.

I can't read, so this is hard.

 

Rather than repeat myself, here is a quote with a few highlights of what I said a few posts back. It was a response to AxleIke when he asked about putting both back wheels in the air and running the engine:

"It does take a very small amount of torque to overcome rotating mass to start a wheel to turning, or to accelerate a wheel, but basically no torque to keep the wheels turning. Since this very small amount is almost zero (because there's almost no resistance to the turning), for all practical purposes it is zero.

(EDIT: There is also a very small amount ot torque needed to overcome bearing resistance.)

But don't grab one wheel and try to stop it. Then your body will be resisting the rotation, suddenly creating torque, and it will take a certain amount of that torque (going only to that wheel, since the other is still spinning free) to fling your body.

By the way, I'm talking about torque split or transfer and not total torque. The 100% going to one wheel can be the total torque, but usually isn't because the wheel will usually lose traction or propel the vehicle before maximum torque levels are reached.

Just to help you inderstand, take a torque wrench and put a socket on it. If you turn the socket without the socket turning anything, the torque wrench will measure no torque. It can't measure the infinitismal amount needed to turn the socket, but the socket still turns. But put the socket on a tightened bolt, and the torque measurement will increase until the bolt turns. Then imagine the socket being a tire, and the bolt being the ground it sits on."

Okay, there is torque turning the free spinning wheel, but it's such a small amount that when expressed as a percentage of what's going to that wheel versus what's going to the other wheel, it mathmatically rounds down to zero percent, while the tire on the ground gets the rest, which would round up to 100%.

So for instance, it could be a torque split of 99.999% going to the wheel with traction and .001% going to the tire without traction.

Since we tend to round numbers up or down to the nearest whole number, that would be a 100/0 torque split.

To help simplify the explanation I never mentioned the very small amount of torque it takes to get the wheel off the ground to spin. But that small amount of torque really isn't enough to make a difference, so for all paractical purposes, a locker can transfer 100% of available torque to the tire with traction.

I just didn't realize that by leaving out that small amount of torque that I would confuse you. I aplologize for that confusion.

 

This thread is very painful to read. Lockers have the capability of transfering 100% of torque to the wheel with the most traction. Any time of a differential that does not have the ability to transfer 100% of the torque to the hooked up wheel can spin the slipping wheel faster than the non-slipping wheel. When both wheels are hooked up on level ground, both open an locked differentials split torque 50/50. As one wheel begins to lose traction, an open diff will reduce the power to the non-spinning wheel so the torque equals what's available on the non-spinning wheel. An open diff always supplies a 50/50 split (+/- a little bit due to friction). That's why you don't go anywhere with one tire off the ground. Both axle shafts are getting ~zero torque going to them.

For instance a torsen style diff may only be capable of a 80/20 split. That is why the tire in the air is turning faster than the one on the ground. That is also why brake drag helps. If you increase the ft-lbs of resistance on the spinning 20% wheel, you increase the ft-lbs on the 80% non-spinning wheel.

All traction adding differentials, whether they're lockers, limited slip, or welded/spool constantly vary the bias side to side depending on traction. That's the basic mechanical principal of what is happening at the wheels. Picture a strain gage on each axleshaft measuring the torque going through it. That's the torque split that's being referred to. A locker has the capability of putting 100% of the engines power through a single side. In application, it'll only be 99.9999...% as William said, due to bearing drag, but if you removed the off-side shaft completely, you would get 100.00% transfer.

The next step is differentials that have a non 50/50 torque split under equal traction conditions (commonly found in awd systems). And taking that the next step further with systems like Honda's Super Handling system. But that really doesn't apply to anything here.