Dave,
Answer me this. Would you rather be driving a rear wheel drive car or a front wheel drive car when traction is limited such as snow/ice or mud/dirt?
This is because the front cuts a path so the rear more easily rolls through, but mainly because a fwd vehicle has all the weight over the driven wheels, if your theory were correct i could take a rwd s-10 and drive in reverse and be fine, but try this in the winter and it won't help, but if you had the same weight over the rear that you normally do in the front it would drive just fine, that and drop the air pressure down slightly ;-) I personally would rather have a rwd with weight because you have more control and can use the engines power via torque steer to aid in my control of the vehicle. A front wheel drive car. This is why having the front end turn slightly faster in a 4wd setup is better.
Actually the reason for this is so you get less push, or understeer during typical stock 4wd operation Having a bigger rear end makes perfect sense because 80-90% of every day use is done with the rear end only. How often do you have your t-case engaged? 10%-20% of the time? And this is probably only when traction is limited enough that youÆre getting slipping on the rear end.
In your analogy I would rather blow up the rear end instead of the front end. If I blow up the rear end I still have the ability to drive and steer. If I blow up the front end there is a MUCH greater chance there could be steering failure too rendering me completely stranded.
Actually with most 4wd rear axles, unless full floating or captured style bearing when a rear axle breaks or a carrier is damaged it is harder to drive out. Most domestic axle are c-clip style, which means when they break they come right the fawk out of the housing, now toyotas, ford 9" and some of the semi float and all full-float dana's are exceptions, but unless you have a full float rear, you can't just pull the axles when you grenade a carrier (which can cause the rear to lock), and you can't simply pull out the 3rd and drive away because the 3rd provides support for the axle ends or else they will flail around madly. Now if you blow a front it's much easier to pull the offending shaft as all 4wd front axles support the weight on a spindle instead of the axle. So as long as you don't tear up a ball joint or a knuckle you can drive a pretty fubard front axle out. Trust me, i blew my front sportage carrier and axle housing in half and had no steering failure, all of that is seperate of the axle. Having the front end pulling by a small fraction such as 4.11/4.10 is not like using grade 2 bolts to hold your winch on in a 6000 lb pull. It isn't any different than driving your vehicle backwards in 4wd.
Most t-cases split power 40-60 front to rear. Try this. Put your vehicle in 4wd low range and romp the gas on a loose dirt road. You'll notice it'll start to get a little sideways if you hold the steering wheel straight. Now do the same thing, but in reverse. You'll notice it stays nice and straight. This is because the rear is getting more power (turning faster) than the front because of the 40-60 split. Thus pushing the car when going in forward and pulling the car when going in reverse.
Most t-cases are part time units that split 50-50 mechanically. They can cheaply call them "full time" if they use wheel speed sensors to engage and dissengage the front axle output (most modern front axles are more like drive flanges because they have no way to unlock the axles from the wheel hubs), but the better "full time" cases do use a planetary to split power front and rear.
I can take my detroit locked to with a part time case (50-50 split and the axles have full power side to side) and hammer down in 4wd and it will still drift slightly on take off.This is another one of those things caused by torque steer, rotation forcse, and suspension loading calculations blah blah mainly, most all wheel drive cars are more biased to the front and still get this.Most suv's with center diffs split the power more to the rear because of control issues and modern weak @&& front ends. Rears are cheap but fronts have more components thus $$$ and it's easier to send the brunt of the force to the rear. ThatÆs why a slightly faster spinning front end would be better because it will put the split back closer to 50-50.
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