It will most definitely bind in 4WD high or low on dry pavement in
turns.  You have a 4WD vehicle, not AWD.  The difference is that a 4WD
has solidly meshed front and rear axles.  Benefit: less slippage, all
power can thoeretically make it to the tires.  Disadvantage:  It is bad
for the system to operate it on good traction surfaces, and you have to
select it manually.

Someone with more knowledge of that 4X4 system will have to chime in on
whether or not shift-on-the-fly is permitted.  Your owners manual
should detail how and when you should shift into 4WD (and if you can do
it at speed, what the speed limit is, etc.)

FWIW, you should not feel any binding in 4WD if you are going perfectly
straight with four evenly sized tires.  Once you turn, the two axles
begin spinning at different speeds, causing binding and wear on all
components involved.  The tires will be the first to slip, saving the
expensive components from severe damage in most cases.  Still, don't
test the 4WD system operation on dry pavement unless you are going
straight.

Toyota MDT in MO

Joe,
Sounds like you have been watching the Subaru commercials and the Audi
ones where they brag how good their "4WD" drives are, the catch is they
are NOT 4WD they are actually All Wheel Drive. The difference is that an
AWD vehicle operates using a viscous coupler between the front and rear
drive lines. That coupler acts like a clutch that can slip if the load
is to high. This allows the front and rear to operate at different
speeds when turning. Your vehicle uses a solid gear and chain drive
transfer case to shift the front axle in/out of gear. It is either on or
off no slippage allowed. That difference sounds minor but it isn't.
Without that slippage a standard 4X4 WILL damage the weakest point in
the drive line if used on a high traction surface.

Your 4X4 system is VERY stout. However there are a few rules you need to
know.

1. DO NOT operate that vehicle in 4X4 on high traction surfaces such as
bare pavement, DRY dirt roads. This causes the drive train to bind up.
Something HAS to give to allow it to unbind from this condition. There
are NO cheap parts in the system!

2. Be VERY careful when driving in 4WD. That vehicle will act MUCH
differently than it does when only the rear wheels are pushing it.

3. 4X4 does NOT mean you can drive 60mph in blowing snow or freezing
rain and not have a problem. Remember that you still have to STOP.
Keep in mind that you are driving a BIG HEAVY vehicle. You CANNOT stop
on a dime, in 4X4 this WILL be WORSE.