In their basic form, a differential is made up of two halves of an axle with a gear on each end connected to a 3rd gear (imagine three sides of a square connected). The gearing arrangement is called an open type differential and is the most common type of automotive differential and is the basis of which more complicated differential systems are derived from. A locked differential is essentially an open differential with the ability to be locked in place, creating a fixed axle, giving your vehicle much greater traction.
Designed to evenly split the power being sent to the wheels and put more power to the ground, (great for cornering) a limited slip differential, (LSD) combines the benefits of both open and locked differentials through a more complicated configuration. There are two types of LSD’s – mechanical clutch and viscous.
Mechanical Clutch LSD’s
This type of limited slip differential surrounds the same core gearing you find in an open diff with a set of pressure rings that exert force the clutch plates that are positioned along the gears. The aim of this is to provide resistance to the independent rotation of your wheels changing from open to locked – providing it with increased traction.
A Viscous type of limited slip differential uses thick liquid in replacement of clutches to create the resistance required to alter the diff’s behaviour between open and locked. With less moving parts, viscous LSD’s are smoother than mechanical.
What cars have limited slip differentials?
LSD’s are used on all types of cars, from Land Rovers to small Hyundai’s; however, they are very popular in vehicles that are designed for high power output and control, like most sports cars are.
So how do you know if your vehicle has an LSD? You can get under the car and inspect for a metal tag or model marking, as some manufacturers (ie – Ford will have an “L” marking) will mark the diff in some way to designate it as a limited slip differential.
Or check with your manufacturer for what to look for. Alternatively, read the manufacturer sticker on the inside of the driver’s side door, as some car manufacturers will specify whether it was shipped from the factory with an LSD.
How do I Know if my LSD’s Need Attention?
If any differentials on your wheels malfunction or wear out, noticeable symptoms can arise. The top 5 symptoms of bad front and rear differentials are damage to the tyres, vibrations, control difficulties and grinding gears. Once you recognise these symptoms, you can act upon it and take your car to a mechanic that specialises in differentials to assess and fix the problem before more serious damage to your car occurs.
Damage to Tyres
When turning a corner, your car’s tyres need to rotate at different speeds to prevent uneven wear and tear. If you have an issue with your differentials, your tyres will wear unevenly and the tread will become worn and flat. Getting your LSD’s checked early on will save you money before your tyres wear down and you need to replace them too.
Whining Sounds and Vibrations
These can be caused by bad LSD’s in a couple of ways. Firstly, your diff’s universal joints could go, causing vibrations in your drive shaft with a whining noise associated. Secondly, your diff’s might have a fluid leak and cause bad vibrations – if that’s the case, they will start to malfunction very quickly.
If you feel like you’re losing some control of your vehicle while driving it, then there’s a good chance something might be wrong with your LSD’s – as the whole point of them is to enhance the control of your car. Time to get it checked.
When your differentials go bad or conk it, you will feel and perhaps hear a noticeable grinding of the gears, especially during change. In addition to a whining noise, you will hear a low humming that gradually gets worse.
Get Your Limited Slip Differential Checked Today
For the sake of your car’s health, and your own wallet, it pays to get your limited slip differential checked. The differential experts at S&G Gearbox Exchange in Perth can identify and replace bad diff’s for any type of vehicle. They supply only the highest quality in parts and service, so get in contact today here, or by calling (08) 9356 9988.