Why Differential Maintenance Is So Important During a Log Book Service Visit

Posted on: 23 June 2022

If you've received a prompt from your car dealer to remind you of an upcoming log book service, you may be wondering what's involved. You may understand the need to replace engine oil and filter and take a good look at the brakes, but why is it essential for the mechanic to take a look at the differential? What is this part, and what can go wrong if it's not inspected?

Understanding the Differential 

Rear-wheel-drive cars feature a back axle that contains a limited-slip differential. This is quite a clever device that can regulate how much torque is sent to each back wheel based on driving conditions. Without this type of component, it would be very hard for your car to turn around any corners without a lot of drama. Indeed, the back wheels would tend to skip or jump rather than turn smoothly, and you would certainly wear out your tyres in short order.

How the Differential Works

The differential is able to achieve the objective with "limited slip." To do this, a sequence of gears will step down the power provided by the engine and gearbox, turning one half-shaft faster than the other. This means the outer wheel will rotate more than the inner wheel when traversing a bend.

Why Lubricant Is So Important

A rear differential will use a different type of lubrication. It will typically be "thicker" than engine oil as friction levels and temperatures tend to be higher in this situation. The lubricant can deteriorate as time goes by and lose its viscosity. When it does so, problems can arise when the metal grinds against metal, meaning that damage is almost inevitable. This is why changing the differential oil during a major log book service is so important.

Closer Inspection

The mechanic will not only remove and replace the lubricant, but they will also look closely at the condition of the differential gearing. They'll be able to spot any early signs of a problem, so they can take action if needed before any failure might occur.

Signs of a Differential Problem

Should the differential start to play up, you may notice an increased vibration and even some strange noises coming from the back of the vehicle. If the oil has not been changed for some time, it may also start to burn, which could give off its own unusual odour.

Keeping Your Appointment

So as you can see, your upcoming log book service visit is crucial. Make sure that you keep that appointment so the mechanic can have a good look at your differential.