You guys missed the 2nd half of the question - what if difference between 4H and 4L.
In 4H, a collar in the transfer case links the front axle to the rear, powering the front axle in addition. In the Ranger, there is a clutch on the collar, so this can be done at any "reasonable" speed.
In 4L, in addition to the collar connecting the front axle; another collar disengages the transmission from the rear wheels and inserts a set of planetary gears. The planetary gears slow down the truck by about 2-1/2:1 (2.48 if you want to be real technical).
So, instead of going 25 in a given gear/rpm combination; you will be going just under 10. Which is useful in off-roading (and a few other situations) when you want to go slow and in control. It also provides 2-1/2 the torque if you are going up something real steep.
But, in order to drive the wheels, 2-1/2 times slower, the "planets" in the planetary are going 2-1/2 times faster. So, it should only be used at slow speeds.
Running at freeway speeds in 4L would result in planets needing to turn >10k and they weren't designed for that.
you will never get to freeway speeds, 45 mph was about all I could get out of my 2000 in low range. the brakes work real good then too!!
When failure happens to something turning that fast, the results are destructive.
So, 4L has no impact on number of wheels powered or amount of "power" to each wheel.
To OP; hopefully, we are helping you understand.
To my expert colleagues, I'm testing you:
And I'd like an explanation on how spider gears increase the pressure.
simple physics. the faces of the teeth are at an angle. not only do they cause rotation to the opposing gear, they also push it away. think inclined plain.
Also, how the right rear (going forward) has less traction; I thought it had same traction, just less load and same force on less load results in it being more prone to overcoming static friction and spin.
my definition of traction (from high school physics in 1970) is how much "sticky" and pressure something has against something else.
we are mixing terms here. I'm guilty. oh yeah, "sticky" is co-efficient of friction. so sticky multiplied by pressure equals traction/total friction.
anyway, sitting still, or in docile motion each rear wheel has approximately the same traction. when you romp on the gas the drive shaft tries to rotate the pinion. because of traction the pinion fights back and doesn't want to rotate faster. that results in the entire axle assembly attempting to rotate about the axis of the pinion. net result is less force/traction on one side, more on the other. yes, I know the pinion also wants to crawl up the ring gear which lifts the front of the car. kinda complicated back there.
The reduction in grip once the threshold is of the preload is surpassed is due to dynamic (sliding) friction being less than static. (Which is why getting off the gas and letting the wheel stop spinning is advantageous most of the time).
Doesn't the SHO have a limited slip in the front axle? My Focus SVT did. And it was real advantage even though it was on the steering axle.
what SHO years are you referring to?
I'll stick to 89-99 for this discussion.
as far as I know, there were no limited slip in the 93-99 automatics. possibly a custom setup someplace, but nothing common.
the 89-95 manuals came open from the factory. aftermarket soon offered a Quaife. its a worm gear torque sensing unit. then along came the Wave Trac torque sensing unit. same worm gears as the Quaife but it also had ramps that increased the bias under load.
And we probably don't want to get into that it will be the left front wheel that spins due to decreased load...