What are the most common reasons for transmission oil leaks From where is the oil leaking from the gearbox? What causes transmission oil leakage?
The transmission transfers the engine’s rotational force to the wheels. A functional transmission is essential for your vehicle to start but not to move.
Your transmission is one of the most valuable and expensive parts of your vehicle. The engine is the most expensive part of your car, while the transmission comes in second. You must ensure that you have enough fluid to cool and lubricate your transmission components. Transmissions without oil can be damaged by excessive leakage. This can lead to serious damage and costly repairs.
Common Transmission Oil Leaks
Fluid pools under a vehicle are the most obvious sign of a leaky transmission. If the automatic transmission fluid is clean and fresh, it will usually be colored red (some CVT transmissions may be green). It is translucent or honey-colored because gear oil is used in manual transmissions.
Transmission oil leaks are most commonly caused by:
Transmission Crankcase gasket
The majority of automatic transmissions have an oil-collecting sump. Between the crankcase cover and the transmission cover, there is a sealing gasket. The gasket between the crankcase and the transmission cover wears down over time, causing oil leaks. Regular transmission maintenance should include replacement of this gasket.
Transmission Output Shaft Seal (Axle Seals)
A common problem is the leakage of the output shaft seal, also known by axle seals. The axle seal is located behind the transmission housing (also known as transmission add-on housing) on vehicles with rear-wheel drive. This seal prevents fluid leaking between the transmission shaft and the drive shaft.
Two output shaft seals are usually required for vehicles with front-wheel drive. Gaskets prevent fluid leaking between the transmissions and axles.
Transmission Oil Cooler Pipes
Automatic transmissions are equipped with an oil cooler. Over time, the oil cooler’s curving pipes can wear out and cause oil leaks. This can cause a liquid puddle underneath your vehicle.
Solenoids and Valves
The transmission system has solenoids and valves that control the fluid flow while the vehicle is moving. Transmission fluid leakage can be caused by a damaged or defective solenoid/valve.
Rod Ball
It is hidden within the engine, so it isn’t visible to the naked eyes. A leak here can lead to an oil leak at the location where the engine is connected to the gearbox.
Transmission Housing/Plugs
There are many moving parts within the transmission. The transmission’s components change with pressure. Extreme situations can lead to cracks in the crankcase or transmission housing. It is possible for fluids to leak from a damaged or hollow transmission housing, although it is not as common.
There is also a plug to drain the oil. Transmission fluid will leak if the plug gets loosening too often.
You should not ignore a liquid pooling under your vehicle. It is cheaper to replace the whole transmission than to replace a defective gasket.
