If you have a real wheel drive car, a lot of the crucial, mechanical action will be taking place behind you as you drive your vehicle along the road. This is because the energy produced by the engine has to be diverted through 90° before it can be transferred to the road wheels. Consequently, if you can hear some unusual noises from "back there" you need to pay particular attention, as something could be wrong with the transmission. To help you pinpoint, you can often tell what is wrong by the type of noise involved. What can you hear?

Whining and Grinding

The vehicle's differential consists of some very heavy duty gears that are meant to engage with each other at particular levels of pressure and at certain speeds. All is good when normal conditions are encountered, but if not, individual components wear out and break down. For example, you may hear a grinding or whining noise whenever you accelerate. In this case, individual components are out of line and engaging when they should not be. If you notice the noise when you take your foot off the accelerator pedal instead, the opposite is true and this means that these components are not engaging successfully when they should be.

Shafts and Bearings

There are two axle shafts, one on each side of the centre differential casing, which connect to the road wheels. If these are at fault, this will result in a very distinctive knocking sound, as the splines on the end begin to wear out. Alternatively, bearings which hold all of these components in place can also start to give out and these will need to be replaced as soon as possible before complete failure ensues.

Why Lubrication Is so Important

When you are travelling down the road at high speed, all the components within the differential casing are interacting with each other under tremendous pressure and high temperatures. While they are designed to do so, you must always ensure that there is a sufficient account amount of lubrication in place, as well. This is why you should always buy the proper type of differential fluid, as it's designed for the purpose, but many people do not pay attention to its condition and may let it run out without proper inspection.

Taking Swift Action

When was the last time that you inspected your transmission fluid? If you know it's been some time and you're now encountering some strange noises, get in touch with a qualified mechanic as soon as possible before you suffer a complete breakdown.