Why two levers for front-wheel drive and differential lock?

[Spanner]

This topic comes up every once in awhile. As does certain hydraulic principals. It astounds me the number of people who just don't understand.

All I can do is try my best to educate those that don't understand

Well, I'm new here and that was the first time I'd heard of it.

Thanks for stopping in here for Bill.

:wrench:

 

[CobyRupert]

Extremely incorrect.

2wd means just that. BOTH wheels are driving.

One wheel spinning and one not does NOT mean its a one wheel drive.

An open differential means that BOTH wheels will apply the exact same amount of torque to the ground.

Get so sick of ill informed people claiming that a 2wd is really a 1wd without a locker or LS, or hearing people claim their 4wd truck is really only a 2wd truck.

"One wheel spinning and one not does NOT mean its a one wheel drive." - Well, uhmm, sorta.... but most people wouldn't say it's 2 wheel "drive" when one tire isn't moving.

Yes, the tire is applying torque, but not enough to "drive" it. If the vehicle isn't moving you can't say a stationary tire is "driving" it.

Then again, neither is the other tire that's just spinning......so....
... technically it's zero wheel drive at that point?

Perhaps it's more accurate, and clearer to non-technical folks if we just call it "1 wheel spin", or "2 wheel spin" when transfer case is engaged, or "3 wheel spin" with 1 locker, etc..

So, no 4WD is not 2WD, but if you're a redneck like me who says "Kick her into 4 wheel squeal", you really should be saying "2 wheel squeal".

 

[LD1]

Logic like that is what muddies the water and gets confused.

I explained it very clearly. BOTH wheels in an open "try" to drive with the exact same amount of force. If one wheel is hanging off a cliff, or on ice, then that takes little effort to free wheel. By default, the tire with good traction becomes equally lazy and only tries with the exact same amount of force as the free-spinning wheel. That's a huge benefit of split brakes on a old tractor. You can require that free spinning wheel to require more torque(by applying it's brake). Thus making the other wheel receive equally more torque.

Just because the vehicle is stuck and not moving, doesn't change the number of wheels trying to drive it.

My 4wd truck is sitting in the driveway. If someone asks me if it's 4wd, I certainly don't reply "no it's 0wd because it's not moving".

If you have nearly equal traction (both tires in similar condition) there ain't much difference between open or a locker.

The more extreme the traction difference is between one wheel and the other, the more pronounced the effects of a locker will be.

 

[CobyRupert]

Just because the vehicle is stuck and not moving, doesn't change the number of wheels trying to drive it. - Ahh, 4WD means it's 4 wheels "trying to" drive. This is something different. Maybe we should call the vehicle a 4WTTD? The word "drive" (and you can look this up) means that there is actual movement, not just force or torque.

My 4wd truck is sitting in the driveway. If someone asks me if it's 4wd, I certainly don't reply "no it's 0wd because it's not moving". -And if the right side is stuck in the mud and the 2 left wheels on dry ground aren't turning, but are leaving you stuck in the mud, I certainly wouldn't call it 4WD.

Okay, okay. I understand. A differential is what it is. I'm just arguing for the sake of arguing (hee hee). I will now stop :stirthepot: Maybe I should go over to the Friendly Politics section of TBN.

 

[LD1]

It's all good.

But some people truly believe that an open diff only permits one wheel to drive the vehicle, and what to argue til they are blue in the face even though they are dead wrong. Just a classic example of not understanding what is really going on, and regurgitating stuff they have heard or read elsewhere. Drives me nuts.

Don't get me wrong, I like lockers limited slips, etc. They certainly can get you out of a bind (or prevent you from getting into one) in certain conditions. But I am a realist an understand 100% how they work in comparison to open diffs

 

[timswi]

As a previous owner of an RTV500 and current owner of an RTV1100 I'll say this...Never checked to see whether 1 or 2 wheels where spinning, (and didn't really care as long as the machine did the job) but since this is about snow plowing; I'll say that on light snow, I'd lock the diff lever and not much worry about 4wd,...In hard snow--I'd engage the diff lock and 4WD..Same as on my 1100. As long as there is something slippery on the ground I'd use the diff lock...I don't really want to get into the posi/Limited-slip/open diff here, since I don't see the issue--What does the machine do was the question as I read it.

 

[JerryK]

Thank God my 2018 ZR2 will have front and rear driver controlled electric lockers..... so I won't be confused as if I am in one wheel drive, two wheel drive, three wheel drive, or four. Or, heaven forbid, if I am limited slipping something at some point.... Yikes, I could even be in a non-posi-tracking mode.... !!!!! I don't see how you folks even sleep at night....... [[[[ ]]]]

 

[LD1]

I don't see how you folks even sleep at night....... [[[[ ]]]]

I do it laying down.

 

[WilliamBos]

I believe most ATV's are permanent "limited slip" differential, few are permanent locked different, and some may be selectable. IMHO, at slow speeds, you should lean and put your weight on the outside tire in a sharp turn so that the inside tire can spin/slip without weight on it and lessen tearing up your lawn or laying rubber on your driveway.

Suzuki, yamaha, Arctic Cat and Honda have a full front diff lock button - engage lock to get out, then disengage. Kawi has a progressive front duif lock, you slide the cable to choose what you want, Polarus has AWD, engages full diff lock based on slippage, and the Can Am Visco QE is similar.

All rear axles are locked, with the exception of turf mode on polaris.

Many big AG tractors have electric front diff locks, they disengage when turning. You do not want the front diff locked all the time.

 

[LouNY]

Bless my soul, some people understand differentials, equal torque to each axle in an axle housing
4 x 2 = 4 axles two powered
4 x 4 = 4 axles 4 powered
6 x 4 = 6 axles 4 powered
6 x 6 = 6 axles all 6 powered