A Pre-runner is two wheel drive only. My 02 Tacoma has the push button 4x4
selector. I also have the push button rear differential lock. I believe the
2000 model year was the last time you could get manual locking hubs on a
Tacoma. The auto locking hubs were optional then.

BBTaco

On my 2002 Tacoma, all I need to do is push a button inside the truck. No
turning of hubs. I don't know what year that changed. Maybe you could find
that out. Perhaps it changed in 2000 and for a few hundred bucks more, you
could have what you want.

I guess you need to know whether your truck has automatic- or
manual-locking hubs. If it has manual locking hubs, then you need to do
two things in order to be in four wheel drive (4WD). First, you need to
physically get out of your truck, go up to each front wheel and turn the
knob from "free" to "lock". You'll know they are locked when the two
arrows line up with each other. It is a really simple procedure. Secondly,
you'll need to shift the transfer case from H2(2-HI) to H4(4-HI), (or
L4[4-LOW] if you need a lot of traction). This is done by shifting the
small shift stick. You will see a small schematic diagram of the wheels,
axles, and driveshafts light up on the dash. You are now in 4WD-mode.

If you have automatic 4WD, you do not need to exit the vehicle. All you
have to do is push a button or turn a knob to lock the hubs. I guess on
Tacomas, this button is on the transfer case shift stick. Once the button
is pressed, you then shift into H4 or L4.

It sounds like your buddy has "on-the-fly" 4WD. All he has to do is push a
single button to lock the hubs and be in either 4-HI or 4-LOW. That is
pretty slick. One disadvantage to this, however, is that if the electrical
components fail, you may be up the creek. You won't have this problem with
manual-locking hubs.

But like I said before, you do not need to find yourself in a sticky
situation to get out and lock your hubs. As soon as you hit the dirt, lock
the hubs even if you are in 2WD mode. You can drive around this way all day
long if you like. You are not going to break anything. Then when you hit or
are about to hit mud, loose sand, etc., shift into 4WD. Don't wait until
it's too late.

One comment about 4-LOW. You should only use it when you really need it.
For a beginner, it is really important to be going very slowly and have
the truck in neutral (if you have an automatic transmission) or depress
the clutch pedal (if using a manual transmission)when shifting in or out
of 4-LOW. If not you could seriously damage the 4WD components. But this
is all in the Tacoma Owner's Manual.
 
I would also recommend picking up a copy of "Shifting into 4WD-The SUV
Owner's 4WD Handbook" by Harry Lewellyn. It help makes sense of all this
4WD drive mumbo jumbo. Good Luck.

They do, and have been doing that for years.  What year truck are you
talking about?

Barry