Written By: Corey Foy

Your vehicle's transmission is a complex system with various components working together to ensure smooth and efficient operation. Thus, an important factor that contributes to the health of your transmission is the choice of transmission oil. Therefore, the right oil is not just a matter of preference; it is necessary for the best performance and longevity.


The Role of Transmission Oil:

Transmission oil plays an important role in ensuring that all moving parts within the transmission are properly lubricated. Specifically, this lubrication is essential for minimizing friction, reducing wear and tear, and facilitating smooth gear shifts. However, the importance of transmission oil goes beyond mere lubrication; it's about using the right oil tailored to the specific requirements of your transmission.


Compatibility Matters:

Transmissions from different manufacturers often have unique specifications for the type of oil they require. Therefore, an incompatible product can lead to a range of issues, including poor performance, increased wear on components, and the potential for overheating. Hence why it's important to follow the manufacturer's recommendations regarding transmission oil specifications.


Case Study: Allison TES 668 vs. Eaton PS 386:

Consider the scenario of using Allison transmission oil (TES 668) in an Eaton transmission that requires a different specification (PS 386). This mismatch can result in poor performance, increased component wear, overheating, and potential damage to seals and gaskets.


The Takeaway:

  1. Get the Best Performance: The right oil ensures that your transmission operates at its best, providing smooth gear shifts and efficient power transfer.
  2. Component Life span: Proper lubrication reduces wear on transmission components, extending their lifespan and minimizing the likelihood of breakdowns.
  3. Overheating Prevention: Correct oil specifications help in dissipating heat effectively, preventing the transmission from overheating and becoming damaged.
  4. Seal and Gasket Health: Using compatible oil preserves the integrity of seals and gaskets, preventing leaks and maintaining the overall health of equipment.



The right oil is more than just a lubricant; it is essential to the health and efficiency of your vehicle's transmission system. Therefore, to ensure your transmission operates smoothly, always follow the manufacturer's recommendations and use the correct product for your specific transmission type. Finally, It's a small investment that can save you from costly repairs and keep your vehicle running at its best. Browse 49 North's lineup here.


If the cold weather is giving your fleet any problems, be sure to check out our blog on cold weather lubrication tips.

Lastly, for any questions about your transmission please call 1.800.463.0354 and speak to our Technical Specialist - Corey Foy or email info@49northlubricants.com.