HOW IT WORKS: Differential Gears

When the truck goes around the corner the riders on the outside of the turn have to adjust their speed to keep even with the riders on the inside the man on the outside has to ride a lot farther and a lot faster in order to keep up with the parade the outside wheels must spin faster than the wheels on the inside because they have a greater distance to travel in the same length of time.

When a wagon turns a corner the wheels can travel at different speeds because each one can turn freely on the axles and in the early automobiles the rear wheels turn separately and only one wheel was connected to the engine but when only one wheel was driven by the engine .

It had to do all the work and it couldn't get a good enough grip on the road to do its job properly so the one wheel drive was soon out of date but if two wheels are locked on an axle so that they are not free to turn separately one or the other as to slide so engineers had to find a way to connect both rear wheels to the engine without sliding and slipping on turns.

The device which makes this possible is the part of the rear axle it is called the differential because it can drive the rear wheels at different speeds the differential looks complicated but once we understand its principle.

It is amazingly simple these two wheels are mounted on separate axles and supported by a frame so that they can revolve freely at different speeds let's fasten a spoke on the inner end of each axle so that by turning the spools we can turn each wheel separately with the bar or crosspiece..