The Importance of Quality Oil Seals for Transmission Rebuilds

Transmission SealsModern transmissions work hard, so shouldn't their oil seals do the same? Inferior seals are one of the most major diagnoses of transmission fluid leaks that can damage the unit beyond repair. When you're rebuilding transmissions every single day, it can be easy to forget how critical these small parts are, but in a system that operates under such high demands, the value well-made oil seals should never be underestimated. In today's post, we're here to discuss the importance of choosing quality when it comes to transmission oil seals.

Causes and Effects of Transmission Seal Leaks

A single transmission can contain dozens of sealing components, all with a specific purpose. If even one of those seals fails, the transmission in the vehicle can begin to leak transmission fluid. A transmission leak isn't simply an issue in itself, however; leaking seals can quickly lead to a multitude of other problems, including total transmission burn out.The purpose of an oil seal is to prevent lubricant leaks by closing in the spaces between a transmission's parts. The seals also prevent dirt and other contaminants from clogging up the unit. A static seal, such as a simple O-ring, fit between two stationary parts, while a more complex, dynamic seal has multiple lips and acts as a barrier between a stationary and a moving part.

Over time, due to varying pressures, stress, and heat inside a working transmission, seals will begin to break down — it's just a matter of time. However, depending on the quality of the seal, that time period can differ dramatically. Additionally, oil seals that accompany more active parts of the unit, such as the input and output shafts, experience a lot more wear and tear, and generally need to be replaced more frequently. And since several of these seals are located inside the transmission, they're tough to service without tearing apart the entire unit. Until a seal actually fails, it can be difficult to detect any sealing issues at all.

Transmission Rebuilder

While proper maintenance and lubrication can aid in the longevity of an oil seal, seal performance is largely dependent upon the overall quality of the seal. Simply put, a poorly made oil seal cannot withstand the pressure fluctuations inside a modern transmission, and will cause more transmission leaks and issues in the long run. Therefore, it's important to choose the highest quality oil seals when rebuilding transmissions in your shop.

Quality Seals Under Pressure

To find oil seals you can truly depend on to hold up long after the rebuild is finished, there are a few key markers of quality you should be looking for. The material a seal is made out of is one huge indicator of quality. Cheap rubber seals don't have the same durability as more innovative materials like polyacrylate, ethylene acrylic, hydrogenated nitrile, fluoroelastomers, and more. Each of these materials has different properties that determine how they perform in different temperatures and environments.

Another true indicator of oil seal quality is its inclusion in the original unit as an OE component. OE seals for rebuilding are the exact same seals used by the original transmission manufacturer to build the transmission, so you can be confident that OE seals will have the highest level of performance as well as the best fit inside the unit.

While no oil seal can last forever, the quality of the seals you choose to install in your rebuilds affects not only the success of that job in the shop, but also the value of your work over time. Using well-made, high quality seals that are able to withstand the high demands of today's transmissions will only increase your productivity in the long-term.