Is 4x4 really 4x4?
 

I am new to Rangers, and am looking at a nice 2003 FX4 4x4. Many years ago I had a Nissan that claimed to be 4x4 but clearly wasn't. How are these things setup, is it a true 4x4 when needed?

Unless it's got lockers front and rear, nothing is "true" 4x4. Best option from the factory would be a limited slip differential (you'd need to decode the tag on the axles to know for sure) But, any open carrier will lose traction if you twist your body and have 2 wheels in contact w/ the ground and 2 up. the 2 up will get power while the 2 on the ground get sheeite!!! Frusterating... But, that's what makes a differential a differential.

It's more 4x4 than a two-wheel drive.

All 2003 FX4 Rangers have some sort of LSD. And they all have 4.10:1 gears.

2003-up FX4 Rangers have the regular Ford "TracLoc" limited-slip (28 spline).

2003-up FX4 Level II Rangers have the "Torsen" limited slip (31 spline).

Until you twist your chassis... then it's no wheel drive...

It doesn't mean the truck is completely useless. Remember this bit of information and drive accordingly. If you plan a lift, get a lift that offers a good amount of flex so it'll be much harder to twist the chassis to the point you lose traction on the two wheels. Also, carry a high lift jack or a buddy with a tow rope.

It's a level II, with 50K miles, looks almost showroom perfect. Sounds like a good base for a fun wheeling/hunting rig.