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How to Determine Why Your Car's Transmission Is Making That Noise

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Human beings are able to distinguish between an enormous number of different sounds and in terms of mechanical components are able to tell whether something sounds "right" or not. This is particularly the case when it comes to an automobile, considering how much time the individual normally spends going back and forth to work on a daily basis. If something is bugging you and there is an unusual sound emanating from the rear of your vehicle, what could this be? What should you tell your mechanic when you first pick up the phone to talk about the issue?

Grinding or Whining

Any noise that comes from the back of the vehicle is likely to be either the suspension or the transmission. What type of noise are you hearing? If it is a grinding noise that seems to get more evident when you accelerate the car, it could be that the internal components of the differential are worn and not engaging properly. If it's more of a whining noise instead, but only appears when you let off the accelerator, this could also indicate internal wear and worn teeth on the end of the gears.


Sometimes, you will notice a clicking noise and this is frequently an issue associated with the axle shafts themselves. When one of the teeth is damaged, it will return this type of distinctive sound. Conversely, should the noise appear when you are turning a corner, then this could mean that the wheel bearings are on their way out and will need to be replaced. While the wheel bearings are to be found on the outside of the differential itself, the gears are internal and will usually require the entire axle to be disassembled, in order to treat.

Looking after the Differential

Always remember that the parts contained within the differential are some of the most complex on the entire vehicle. This unit has to convert the power produced by the engine into a form of traction that can be delivered to the wheels themselves. This type of operation can by itself introduce very high temperatures and a lot of friction. While the parts are designed to work in testing conditions, it's crucial that the right type of differential fluid is used. When this is not the case these parts can overheat very easily and break, often without warning. As a consequence, you should choose the right type, viscosity and consistency of differential fluid, as this will vary from manufacturer to manufacturer.

Asking the Expert

In the meantime, you may now be able to advise your mechanic about the specific type of noise that you're hearing, before you take the vehicle in for action.