Differential Units

At Universal Motors our fully equipped workshop in Thomastown, provides differential repairs and replacement for all makes and models.

Why use a Differential?

When a car turns a corner, one wheel is on the “inside” of a turning arc, and the other wheel is on the “outside.” Consequently, the outside wheel has to turn faster than the inside one in order to cover the greater distance in the same amount of time. Thus, because the two wheels are not driven with the same speed, a differential is necessary. A car differential is placed halfway between the driving wheels, on either the front, rear, or both axes (depending on whether it’s a front-, rear-, or 4-wheel-drive car). In rear-wheel drive cars, the differential converts rotational motion of the transmission shaft which lies parallel to the car’s motion to rotational motion of the half-shafts (on the ends of which are the wheels), which lie perpendicular to the car’s motion.

Common differential problems include:

  • Whirring noise while decelerating at any or all speeds.
  • A whining noise while accelerating between certain speed ranges, e.g. between 80kmh and 90 kmh.
  • Rumbling noises as you increase speed which change while turning
  • A clunking or clanging noise every few metres.
  • When cornering a clunking noise occurs.

A differential unit (commonly known as a ‘diff unit’ or just ‘diff’) has three main functions:

  • Assist with transferring power to the wheels.
  • Provide the final drive gear ratio of your car.
  • Enable the wheels to turn at different speeds while cornering.