What does the car differential (diff) do?

In rear wheel drive cars the differential (diff) system forms a connection between the cars transmission and the horizontal axis of your car. This allows for energy to travel from your car’s engine to the wheels. When the differential (diff) is operating correctly, it will be able to transmit energy to the wheels while allowing them to operate at different speeds (hence the name differential).  This allows your car’s ABS system to work correctly and improves your car’s ability to make turns.
Learn more about how the differential works >

The differential requires lubrication in order to function smoothly. The role of the differential gasket is to keep all of the lubricating oil sealed inside. If the differential (diff) gasket becomes loose, damaged or cracked the diff oil can leak out, affecting the operation of the interior components, including the pinion gear, side gears, spider gears and crown /ring gear, plug differential (diff) bearings), left axle and right axle. 

A differential oil leak will not immediately make your car undrivable, however, the problem will become worse over time due to the the increase friction and heat caused by low or no diff oil. 


Causes of a differential (diff) gasket oil leaks:

Wear over time – The car differential gasket can be put under a lot of stress. Because of this, the diff gasket can wear, eventually resulting in a new differential gasket needing to be installed.

Incorrect installation – If the differential gasket was not installed correctly during a previous repair or maintenance, it may not provide an effective seal, leading to oil leaks. Incorrect torquing of the differential cover bolts or improper alignment of the gasket can be factors here.

Overfilled with oil – Excessive oil levels in the differential can create pressure, causing oil to seep past the gasket. This can occur if the differential was overfilled during an oil change or if there is a problem with the breather valve, which regulates pressure inside the differential housing.

Excess pressure – In rare cases, high amounts of pressure can result in the differential gasket becoming loose. This can cause differential oil to leak. 

Physical damage- If the differential or the differential cover has sustained physical damage, such as dents, cracks, or warping due to an accident or sudden impact, it can compromise the integrity of the gasket seal, leading to leaks occurring.


What are the symptoms of a failing car differential (diff)?

Grinding noises – When oil is leaking from the differential, the car differential won’t be able to operate as smoothly. This can create loud grinding or whining noises from beneath your vehicle. These noises may become worse over time as the car differential parts wear out or diff bearings become noisy. 

Clunking or banging noise – A failing differential may produce clunking or banging sounds, especially when shifting gears or during abrupt acceleration or deceleration. This can indicate excessive clearance or worn gears within the differential.

Vibrations while driving – If you feel vibrations or shuddering coming from the drivetrain, particularly during acceleration or deceleration, it could be a sign of a failing differential. Worn or damaged differential components can cause uneven power distribution and result in these vibrations.

Oil leaks from under the back of your car – When the differential gasket is leaking, small puddles of oil may appear under your car. 

Difficulty turning – A failing differential may make it difficult to steer the vehicle smoothly, especially when making tight turns. You might experience increased resistance or a jerking sensation while maneuvering the vehicle.


Car Differential (Diff) Oil Leaks fixes & New Gasket in Hamilton

Is your car differential leaking oil and in need of a new differential (diff) gasket? If so, we can help!

At Grimmer Motors, our skilled , honest and friendly mechanics can diagnose problems in your car’s differential system. We can then provide you with high-quality  replacement services (if necessary). 

For differential services and new differential gaskets in Hamilton, contact Grimmer Motors today!


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