I just replaced the timing belt in my '96 ranger 2.3, 177K, original belt. The belt has lots of surface cracks, looks very worn. I've been playing with the old belt, trying to break it. These belts are tough! I have tried stretching, bending, just about everything to break it and I can't, these belts are tough! I'm surprised that these things ever fail.

 

The main cords in the belt don't usually break , it's the teeth themselves that strip off .