Kikki's Workshop Q&A: Let's ask Kikki ! Kikki's Workshop
How does a skid steer loader turn ?
A skid steer loader's wheels themselves can not change the direction, and it does not have a joint within the body like a wheel loader. It makes you wonder how it makes a turn, doesn't it ? A skid steer loader in fact uses the difference in spinning speed between the right wheels and the left wheels in order to make a turn.

It works the same for hydraulic excavators and other construction vehicles with crawlers. By making the left wheel spin slower and the right wheel spin faster, the vehicle turns towards left. Forklifts also use the same method to change the direction.
It controls the direction with the difference in spinning speed between right and left wheels.