Why Auto Gearboxes May Leak

Posted on: 11 July 2017

It is important for you to pinpoint why the gearbox of your car is leaking before you attempt to fix that leak. This article discusses some of the possible reasons why auto gearboxes may leak. Use this information to investigate the leak in your gearbox so that you can select the best repair technique to fix that problem.

Sealant Deterioration

The traditional sealants that are used in gearboxes may deteriorate over time due to the effect of heat and other forces acting on those sealants. The net result is that gaps can start developing within the sealant layer until the gearbox starts to leak. The best way to fix this problem permanently is to select a modern sealant that can withstand the forces that caused the previous sealant to fail.


Vibrations in the components that are close to the gearbox can also cause that gearbox to start leaking. Those vibrations can exert a huge strain on the piping that carries oil to the gearbox. Leaks can then gradually develop as the piping gets dislodged from its anchorage due to prolonged exposure to vibrations. It would therefore be futile to fix the leaks if the excessive vibrations have not been resolved since the same problem will keep recurring. A lasting solution can only result when the vibrations are brought under control by tightening any loose components, for example.

Temperature and Pressure Changes

Another common cause of gearbox leaks is the change in the temperature and pressure within the system. These changes can be caused by several factors. For example, the frequent towing of heavy loads can put an excessive strain on the gearbox system. This can causes the gearbox to overheat to the extent that a fluid line may develop pinhole leaks. Those leaks can then start getting worse as the gearbox is subjected to bigger loads than it was designed to handle. The use of the wrong transmission oil can also cause the temperature inside the gearbox to spike. This is because the oil will be unable to keep the components well lubricated in order to avoid an increase in temperature due to friction. Leaks can then result if the correct oil isn't used.

As you can see, tracing a gearbox leak to its root cause can save you from incurring needless costs in the futile cycle of dealing with symptoms. It is much better to consult a gearbox repair professional for an expert opinion so that a lasting solution can be found for those persistent leaks that you have been witnessing.