With everything locked, and three wheels in the air, the wheel on the ground would get all of the torque, while the three in the air would rotate with the wheel on the ground, not spinning free. So the wheel with traction in this situation would get all of the power, which was the original question.

Yes in the situation you describe, the other three wheels would spin in unison with the one wheel with traction, because they are each receiving 25% of the power output from the transmission. However, there is no shifting of power from one wheel to another or one axle to the other due to traction loss in a ff/rr & center diff locked situation. In this situation all 4 wheels spin at the same rate - regardless of traction. If any of the 4 wheels has traction the truck will move - if none of the wheels have traction the truck will not move.

I think we are really saying the same thing, just trying to avoid the OP thinking that 100% of the power goes to one wheel in a fully locked rig. Just as a locked center diff takes power 50:50 front to rear axle, front and rear lockers take that 50:50 and make it 25:25 at each wheel front and rear.

Driving on a flat beach it may not matter one way or another, I see minivans driving on some of them.. Now if you have sand dunes to climb you will want to lock the center diff. Otherwise as you give floor the gas pedal to get the wheels spinning the brakes will apply to stop the wheel spin and forward motion will stop . Lock the center diff and you can get the tires spinning fast to get you over the dune. In sand low tire pressure and lot of tire speed is what keeps you moving.

100% of the power does go to one wheel when fully locked with three wheels in the air. It's as if the other three wheels don't exist, they're no longer putting out any force, so no force comes into them. The only thing resisting the engine force is that one wheel with traction.

In my 4R with the center diff locked, I would have one wheel with traction, and the opposite wheel on that axle would get matching resistance from the brake, so those two wheels would each get 50% of the engine power.

Scottm has this. I'm not a fan of the oft repeated phrase "50/50 torque split" to describe center lock because it's very misleading. Torque can only follow traction because in order for there to be any torque, there has to be something to push against. So with only center diff locked, front or rear can receive 0-100 percent torque depending on traction.

The equal split is actually what an open diff does. One wheel spins and another, connected by differential, receives the same amount of torque -- which may not be enough to move the vehicle.

Agreed. It is more accurate to say that when the center diff is locked, that the front and rear driveshafts turn at the same speed.

An understatement.

One causes all sorts of confusion and the other is a perfect description.

x2 or is it x3

Scottm has it, M1911 and JB are correct.

Unsure of the tone of your post but if it was suggesting overkill I would submit that the OP's question has long been answered and that in the ocean of confusion created by "50/50 torque split" a few drops are at least as good as one.

Tone is good! I was adding a vote/opinion agreeing with you guys. If anything I was/am 'overkilling' it. I totally agree about 'confusion' about this and other aspects of 4wd especially the 4th gen system.

It seems this topic is tough one for folks to get their arms around. The other interesting thing, to me, about this system is once the proverbial light turns in someones head they've "got it" 100%, no looking back. People either get Torsen, center diff-lock ATRAC, VSC etc or they don't. It's such a great system and even better when the end-user fully understands it (that's why I like threads like this). The more people know the better they can use/enjoy the expensive, cool equipment they've chosen to own

The only reason I chimed in was to add 'support' in the hopes next person with this question discovers this thread in their search AND when they're done reading it they're less confused rather than more confused.

OK, now it's overkill.

OK I get it, thanks. Looks like this won't be an issue for me as my beach driving is right along the water to get around flooded areas on trails. No dunes, but nice to know.

My biggest challenge is mud, would you suggest locking the diff would help there??

Yes.

So which one is it? People are giving 2 different answers on this. Some have said each wheel gets 25% of power regardless if it has traction or not. Others said that if 3 wheels are off the ground then the wheel with traction get 100% of the power which is hard to believe. Because why would they have offered a TE for 2009 with ATRAC.

If each wheel gets 25% of the power than this is not enough power to pull the rig up hill with just on wheel.

All of the confusion is basically around the semantics of this discussion... people with true knowledge of physics will agree that if a tire is in the air, it can do no work as it is not appying force. Maybe a different explaination will help... without worrying about what percentage of "power" is going where.

If a differential is "locked", regardless of where your wheels are, both sides of that differential will rotate at the same speed... whether it's your front, center, or rear differential. Think of "locking" as physically connecting the two shafts the differential is connected to. When speaking of an "open" differential, you could say that the "power" will go to the wheel with the least amount of resistance. Ever turn a corner and punch it in a rear wheel drive car and have the inside tire break free and spin? Ever try climbing a gravel hill (in a vehicle without A-TRAC) and have the tire that starts to come off the ground break free, spin, and leave you stuck in that position? That's an open differential sending "power" through the path of least resistance. A locked differential will keep both sides rotating at the same speed... if one tire comes off the ground, it can't spin any faster than the other tire (same axle, of course) that's on the ground. Our 4Runners have "open" differentials, but utilize the vehicle's brake system to grab the slipping tire and force "power" across the differential to the tire with more traction.

I recommend experimenting with your 4Runner in an off-road situation and watch some real rock-crawlers for an understanding of what it means to "lock" a differential.

I'd say, "Now that's overkill", but I wanted to try and offer an explanation in different words... hopefully, it will help.

~Doozi