is it a differential lock or positraction type?
how well does it work?
should I look for 4 wd in 2010 or 2011 f 150?

 

Traction Control is a different animal from a L/S or locking rear axle. Traction Control is where the computer monitors the wheel speed sensors. When it detects one wheel start to spin faster than the other (wet, snow ice), the computer de-tunes (stutters the engine) so that you don't over spin the wheel with less or no traction.