I've seen many people, including me, complaining that the SR5 and TE no longer have a center locking differential.
Someone please correct me if I'm wrong, but I believe that all the new 2010 4x4's, including the SR5 and TE,
do have a locking center diff. When you put it in 4WD, does it not lock the center diff so it's 50/50 front/rear split? I believe it does, just like my old '00 SR5 did. From what I've read, I believe the problem is that the SR5 and TE no longer have the ability to run in 4WD on dry pavement (what Toyota used to call "multi-mode" in the olden days.) In other words, the only way to activate 4WD on the new SR5 and TE is to lock the center diff. So yes, they DO have a locking center diff, that's how it gets power to the front axle.
I believe it was the '98 Limiteds that first got the socalled "multi-mode" 4WD system that would allow you to run in 4WD on dry pavement (a feature that became standard on all trim levels in '01). The multi-mode would provide power to both the front and rear, but it did NOT require you to lock the center diff in order to provide power to all 4 wheels - therefore allowing you to run on dry pavement because there would be no binding. Of course, with multi-mode you could ALSO lock the center diff if you wanted to for more heavy duty 4WD applications.
All 4WD fourth gens with the torsen center diff could also run in 4WD on dry pavement because the center diff didn't have to be "locked" in order to provide power to front and rear. But once again, you had the option of locking it when you wanted to. This was an ideal system IMO, made better only by the addition of a rear locker on the 4th gen '09 Trail Edition.
So to summarize, it's not the loss of a locking center diff that we should be lamenting. Rather, it's the loss of the ability to run it in 4WD with center diff UNlocked which is what you need to run 4WD on dry pavement (except for the Limiteds of course which retain this feature in '10).
I'm still not sure though that I've read anything definitive on this yet - I want to wait until I actually sit in a 5th gen and read an owner's manual for an SR5 4x4 to be sure. I say this because I still can't believe they would take such a major step backwards on non-Limiteds until I read it with my own two eyes
