if an atv is powered by only 3 wheels then why does it not pull to one side??
3wd is an impossible concept given the drive line of these machines.
what you imply is that if i jack my car up, all power will come thru one wheel?? that is down right retarded. the vehicle will pull to the point of being undriveable. if in fact this happens to your car, its a direct result of the brakes dragging more so on one wheel then another. you can verify this by a difference in wear of the 2 sides brake pads or shoes as the case may be.
limited slip works by locking the wheels together as one unit when one wheels rotation exceeds the other by a certain amount. once that rotaion speed is exceeded then they are locked until they both regain the same traction.
an open differential, what just about every car in the world has, applies the same torque to both wheels at all times. but it can never give more then the least amount of traction available.
thats the thing that gets the simpletons hung up. is when u loose traction on one wheel and it spins. ok well both wheels have the EXACT same amount of torque as the one sliding. they are both giving the same amount of torque to the ground.
polaris "true 4wd" is nothing more then marketing, its kinda funny that they have taken this so far as to dumb down the general population.
i have nothing wrong with any machines, but boy that piece of marketing sure made every one dumb.
i went to my local polaris dealer and asked the sales guy, the guy who makes money when he convinces you to buy a machine, and asked him exactly how it worked. when i posed questions to him, he just kept repeating the same thing "only one with tru 4wd", ok but that did not answer my question, of how it works. eventually he sent me to the mechanic.
after a pretty long debate, i have to give him credit for having patience and taking the time to discuss this, after a pretty long debate, he realized that the whole 3wd thing is a myth.
jack your machine up all 4 wheels in the air put it in 4wd, do all the wheels spin?
of course they do.
yes if you grab one wheel the other will spin, but pay close attention and you will see, it spins twice as fast, twice becasue its now getting the rotations from the other wheel. that alone implys that wheel is doing work, and the fact that all four wheel spin in the air, is the exact same situation as if u were driving downa trail and all four wheels had equal traction.
i read above some monkey was saying that a limited slip only applied traction to both wheels if they both had traction, and someone actually agreed with him, so i could not help my self and post a reply even if this topic is 5 years old.

 

I feel like the 4wd actually works really good. If I get in a situation where the wheel on the ground isn't turning I just grab the front brake a bit and it starts going. Easy enough right?

 

The answer to this driveline debate is simple.

If you have an OPEN differential then power is applied equally to both wheels provided they have equal traction. If traction is not equal, the tire with less traction spins as it recieves power of both wheels, and the other tire stays still.

A limited slip differential regardless of design uses a mechanism to lock both wheels to a certain extent, for arguments sake lets say 15%. If there is a difference of traction between 0 & 15% between the tires, both will turn equally. Diffence in traction greater then 15% and it operates like an open differential.

A locker as the name implies will lock both wheels together regardless of a difference in traction.

An open differential makes steering easier, and lessens streess on front end parts. A limited slip works for MOST of the people buying Honda ATV's, they work in mud holes, not so much crossing ditches or rock climbing.

A locker (I have a spool in my Foreman) definantly makes steering harder when going slow, harder the surface the worse it is. i've been running it now for 6 years with no noticeable difference in front end parts actually wearing out. Traction is great for the tangly trails I ride, but its not the end all, you still get stuck. For people thinkign that engaging a locker is a magic button to get unstuck, well you can easilly get stuck with all 4 wheels turing when you try. On tangly trails, its definanltly better with a locker, and I would not un-install it to get easier steering.


Theres probably a whole lot of reasons Honda does not offer a locker from the factory. Patent issues may be one as there's not a whole lot of different ways to engineer one, and the market demographic that they cater to is probably not demanding one. For trail riders its not a necessity, for the extreme riders there are other brands to choose from, and overall is probably a small share of the market.

 

Holy old thread. The four wheel drive works fine for my needs. When I get stuck a locker wouldn't help me get out anyway. thanks for the great explanation though. Makes sense.

 

I always say, "The only difference between two wheel drive and four wheel drive is you get stuck further in the woods." On the other hand, I've come very close to not making through some deep mud/waterholes. I want as much traction as I can get.

 

@Action450, your talk on limited slip could not be more contrary to the name or physics of such devices.

I have no intention of flaming anyone, the reason I even stumbled on this thread was a freind of mine, was trying to tell me her polaris was tru 4wd and my arctic cat was only being driven by 3 wheels. i laughed out laoud as i was imaging the pull it would have, how it would be completely undrivable.

limited slip as the name implies, means to Limit Slip. Which we could extract the meaning to also be, To Allow SOME Slip.

In order for you to be able to have manageable steering you need the front wheels to be able to have some difference in rotation. An open differential as WELL as a limited slip provide this. When you put your front locker on, the steering is heavy, as it does not allow this slight difference in rotation.

The way a limited slip differential works, it allows some slip, to use the previously mention numbers, lets say it will allow up to a 15% difference in rotation between the 2 tires, once the 15% threshold is passed the differential locks the 2 wheels. They will remain locked until they are below that 15% number at which time the differential returns to an Open State.

The reason people will talk down about limited slip versus a full locker, is that short time when there is a slight loss of traction, the time it takes for the limited slip to engage. the delay from the equal traction to the time it takes to reach the 15% difference, to the diff locks itself.

I dont care about one design or the other, what is driving me insane is the amount of disinformation throughout the internet. It also makes me uneasy to think there are mechanics out there who do not fully understand 4 wheel drive, but they will try and fix them.

Sorry to drudge up an old thread!

If you still disagree with me, check out wikipedia on limited slip. There is no mention of atv in there, only cars, but its all the same.
Limited slip differential - Wikipedia, the free encyclopedia

 

Quote: The way a limited slip differential works, it allows some slip, to use the previously mention numbers, lets say it will allow up to a 15% difference in rotation between the 2 tires, once the 15% threshold is passed the differential locks the 2 wheels. They will remain locked until they are below that 15% number at which time the differential returns to an Open State. /quote

Cant happen, maybe in therory, but device used in the front end of honda ATV's up to 2001 (Wet Clutch) it does not work this way or I would not have bought a locker. When you jam up one wheel with the other freewheeling you are well above the 15% threshold, and low and behold the wheels are not locked, but one is spinning uselessly.

What your referring to is a Posi Traction Rear end like those used in Muscle cars, not a clutch style limited slip differential. The device you described is EXACLTY how a Detroit Locker operates, NOT a LIMITED slip differential.

 

QUOTE
What your referring to is a Posi Traction Rear end like those used in Muscle cars, not a clutch style limited slip differential. The device you described is EXACLTY how a Detroit Locker operates, NOT a LIMITED slip differential.
QUOTE

to quote the WikiPedia article you so clearly did not read.
"In the 1950s and 1960s many manufacturers began to apply brand names to their LSD (LIMITED SLIP DIFF) units. While Packard pioneered the LSD under the brand name "Twin Traction" in 1956, the most famous of these was Chevrolet's "Positraction". Since then, Positraction (often shortened to "positrac" or merely "posi") has become a genericized trademark for LSDs."

SO, what that means is YES! I Am refering to "posi traction", also known as LIMITED SLIP DIFFERENTIAL. NOT a differentail locker.

a differential lock, does not lock itself, a differential lock requires a manual process to actually enagage it. when its engaged both wheels spin the same no matter what. and even if both wheels are not moving, they are still mechanically connected. a big difference between the 2.

limited slip differentials use clucth packs, clutchs wear out rendering them useless. if you were to try and test a limited slip differential whose clucth packs were worn beyond service, then yes, you are right, it will act as an open differential.

i am just trying to clear the air of misused, misrepresented terminology. nothing more nothing less.

 

mr fourwheeldrive expert......put a honda in a mudhole and tell me how many wheels spin.......the answer will be 3 .....the front wheel that is spinning will be turning twice as fast as the rear ones ......that is what we call 3 wheel drive.....yes power is applied to all four wheels equally but it doesnt mean all four wheels will spin

 

also.......if you know how the polaris system works then you would understand true 4 wheel drive.....not bashing on you just stating facts