ALL ABOUT DIFFERENTIALS
Every car has at one, but yet it’s one of the most misunderstood areas of a car’s performance. We are of course talking about diffs, or differentials to give their full name. There are a number of types of diff available, each one having its own unique characteristics. Some will be suited to road cars, some to race cars, and some to off-roaders. Also, diffs in front-wheel-drive, rear-wheel-drive, and 4x4 cars will all need to behave differently to give optimum performance. And there’s also the ‘electronic’ diffs which utilise on-board computer systems to work in conjunction with mechanical components to deliver improved performance. So, let’s take a closer at these different types available, get our heads around how they work, and try to understand which one is best for you…
WHAT IS A DIFF?
Firstly, we need to understand what a differential is, what it does, and how it works. Differentials aren’t a new invention, rumour has it that they have been around for over 3000 years with the ancient Chinese first using differential gearing in the South Pointing Chariot.
Modern diffs are a far cry from this first invention, but the principals remain pretty much the same. A diff’s job is to allow the driven wheels to rotate at different speeds and allows three shafts to rotate at different speeds at the same time; the input shaft, and two output shafts (to each wheel of the axle). The input shaft receives power from the transmission, and the differential then transmits this power to the driven wheels via the driveshafts.
So, why do we need a diff then? A diff is needed to allow a car to go around corners. If you draw a radius for the inside
