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

[Rustyiron]

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

I have know how to "read" this, and what it meant for years, BUT never had it explained to me. I thought it was driven wheels, (duals only count as one) 4x2 was 4 wheel locations with one axle driven. Never really thought of a wheel on a steering spindle as an axle but it is.:thumbsup: Thanks Lou.

 

[bcp]

And my bicycle is a 2 x 1

Bruce

 

[Raspy]

"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".

The easiest way to remember the way differentials work and understand what they are doing is to remember this:

An open differential means: both wheels always have equal torque and run at different speeds.
A locked differential means: Both wheels always have unequal torque and run at the same speed.

A limited slip means there is resistance inside the differential to the wheels turning at different speeds. This is done with gears or clutches. The wheels are trying to turn at the same speed, but it can be different, so the torque between the two can be different. This helps get unstuck, but isn't locked. It's somewhere in between locked and open and the amount varies by design of the unit.

"One wheel drive" is completely inaccurate when discussing differentials. If one wheel is spinning and the other not spinning, in an open diff, it simply is doing what diffs do, namely, equal torque and unequal speed. One wheel on ice and the other on a rock. One spins, but they are both applying equal torque to the ground.

Watch this excellent training film about how differentials work:

Around The Corner (1937) How Differential Steering Works - YouTube

 

[CincyFlyer]

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

I will note that "4x4" is commonly used to describe a Jeep.

 

[Raspy]

4X4=16, last I checked.

 

[LD1]

4X4=16, last I checked.

In the case of Ford trucks, that's true.

4 wheel @ 4 hours each = 16hp total:stirthepot:

 

[dnw64]

Watch this excellent training film about how differentials work:

Around The Corner (1937) How Differential Steering Works - YouTube

That was awesome. Thanks!

 

[dnw64]

I will note that "4x4" is commonly used to describe a Jeep.

Well, most Jeeps are 4x4s (other than Post Office Specials), 4 axles, 4 powered. Not sure what your point is?