Its similar. The T/C is doing the work. The outcomes are somewhat different. Specifically, this 4WD auto on the suburban (which seems to be the closest equivalent to the full-time 4WD system if I saw all the modes correctly), is completely RWD biased until a loss of traction occurs, in which case power is distributed to the front (if Im reading this correctly). Ours is basically just a 4WD sr5 at all times, some fun front/rear power distribution bells and whistles.

My sense is that you could be alluding to the center diff, as a component of the T/C not somehow being a “true” center diff. Im not sure I agree, but from a purists perspective, the assessment that it is not a standalone component is 100% accurate. To me, it’s like saying turducken is no longer duck, or turkey, or chicken, simply because they’re all encapsulated within one another. Cheaply made parts with such a sophisticated role/operation could easily be a problem, but this system was used on all 4WD 4th gens, as well as the LC and GX. Its not a one-off. Judging by the lack of complaints we see about it, id say it’s proven to be reliable over its many years out in the wild.

Not alluding to anything. Just wondering where the heck it is as there is only so much room on these things. To me “center diff” implied a whole separate differential physically separate from the transfer case.

Glad these things seem to work, because the NVG 246 on my suburban has had its share of issues. The issues have all been electrical dealing with the shifting and it’s been a huge learning curve for me to diagnose.

The center diff is inside the transfer case. Have a look at this video. Scrub to 22:56 to see the guts of a center differential transfer case explained.

https://www.youtube.com/watch?v=ESm0PPBkAQQ&feature=youtu.be

If there’s a way to embed videos on this board I can’t find it.

Don't think of the T-case center diff as resembling a "normal" diff in any way visually, as they are quite different.

Here are some other videos related to Toyota transfer cases. They don’t address the center differential (but that was addressed in the video I linked to above) but they provide a crystal clear understanding of what’s going on in the transfer case.

This first video shows all the internal components of the t-case working together.

VIDEO LINK

This second video shows the internal components working in a cut-a-way case, with a front propeller shaft and a cut-a-way front differential. The workings of the ADD are also explained.

VIDEO LINK

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I just got a limited. Can anyone tell me what happens in a situation where i am in H4F in snow/ice and a have one wheel without traction and spinning in front and rear will this caus me to just not move and be stuck b/c all power will be sent to spinning wheels?

I just got a limited. Can anyone tell me what happens in a situation where i am in H4F in snow/ice and a have one wheel without traction and spinning in front and rear will this caus me to just not move and be stuck b/c all power will be sent to spinning wheels?

Switch to L4L and engage ATRAC.

Search YouTube and you can find videos of it in action.

Oh. But in H4F if one front and one back wheel is not getting traction and spinning does the other non spinning wheel on same axel get power tranfefed to it or does all the power go to the spinning wheel?

Here's a solid recent video on the differences between how a Toyota full-time 4WD vs. part-time 4WD transfer case works.

https://www.youtube.com/watch?v=oErPa0aA37c

You are correct. In the unlikely event that one front wheel and one back wheel are completely without traction, you will probably be stuck in H4H, or even H4L. This would most likely only happen in an extreme off-road or extreme ice condition.

In that case, you would put it in L4L and use ATRAC.

In my opinion, the all wheel drive system on the 4Runner Limited is probably the best out there if your primary concern is safely navigating snowy/icy roads.

If ATRAC is engaged, then the spinning wheel will have the brake applied to it, so the non-spinning wheel with grip will get power. But I believe ATRAC only works in low range.

Best would be "lockers". locking differentials, then both wheels are forced to turn at the same speed, and the car will move forward because one wheel has grip.