What is it: Independent Suspension-Each wheel and tire per axle is attached directly to the frame using one, two, or more control arms. The axle’s differential housing, containing the axle gears ...

See All 20 Photos. As routine ... The wheel bearing, of course, is that cage of rollers that allows the wheel hub to rotate freely on the axle's spindle.

Mercedes-AMG helped launch the 6×6 craze when it turned the G63 into a behemoth with six wheels and portal axles in 2013. Just about every type of truck has gotten the add-an-axle treatment since ...

Finally, the axle wheel hubs are put together and ready for use in heavy-duty trucks, making sure they can handle tough jobs and last a long time. The Skills.

And finally, parts would have been added to the end of the axles for attaching independent wheels. The authors estimate that these innovations likely took place over 500 years.

More importantly, “this ‘wheel and axle’ revolutionized human technological history by transforming linear to rotary motion and causing parts of devices to move,” per the study.

The earliest archaeological evidence for an actual wheel dates back to about 5,000 years ago, a wheel found in Slovenia’s Ljubljana Marshes in 2002. But the Natufian culture that produced the ...