Read pg 50 - Worm Gears - in book "The Way Things Work" Watch Videos: Worm and Worm Wheel Gear - Working of Worm and Worm Wheel - Soumen...

Read pg 49 - The Differential - in the book "The Way Things Work" Watch Videos: Differential - How Does it work - Lesics - 4:46 min...

Read pg 48 - Bevel Gears in book - The Way Things Work Watch Videos: Bevel Gears - Introduction to Bevel Gears - Vincent Ryan - 1:36 min...