Other Articles |  April - 2023

A Slippery Slope – Allison Fluid Changes

Allison transmissions have long been the standard for truck and off-highway vehicle applications worldwide. However, like everything else in our industry, change is constant, and keeping up with the changes can be a challenge, even for those directly involved in the industry.

Unlike most OEMs today, Allison believes that access to updated information is critical to keeping the repair side of the business informed, therefore limiting the mistakes made. This ultimately results in happier customers and repeat business for the company. While most OEMs today do not share much information with their dealerships and little on the aftermarket, Allison has been very transparent with product changes and issues.

Like everything else in this industry, fluids are constantly being updated, and we have seen more changes to the fluids in the last five years than we have throughout the life span of the automatic transmission. Like other manufacturers, Allison has made changes to their transmissions, requiring the fluid to be updated. Generation 6 units were introduced last year, and with that, many changes occurred, from the electronic control system to internal changes.

Fluid updates are a part of life in our industry, and it is imperative that everyone understands which fluids are available in our industry and which fluid is required for your unit. Allison, like other OEMs, does not manufacture the fluid themselves but instead certifies specific manufacturers to produce the fluid with their specific blend of chemicals for the marketplace. Like other OEMs, Allison sells fluid through their supply chain as “Allison Transmission Fluid.” Rest assured, as long as you are purchasing the fluid through a “licensed” supplier, the fluid will work in your Allison application even though it may not be in the Allison container.

Currently, there are four fluid specifications you will find listed in your service information for your Allison “on highway” applications; these are:

  • TES 389: A mineral-based fluid similar to Dexron III. TES 389 utilizes industry-standard recommendations for fluid change intervals.
  • TES 295: A synthetic fluid with extended drain intervals and enhanced temperature stability and performance.
  • TES 468: A synthetic fluid with extended drain intervals approved for hybrid applications.
  • TES 668: A next-generation synthetic fluid that supersedes TES 389 and TES 295 fluid applications. It is now the factory fill for all new and reman Allison applications. The fluid can be used in all Allison 1000, 2000, 3000, 4000, and hybrid applications, but it is not currently certified for the TC-10 applications. In addition, the fluid can be mixed with any of the other Allison fluids. Currently, there are 23 suppliers licensed to produce the TES 668 fluid; these include Castrol, Shell, Petro Canada, Chrysan, Chevron, Citgo, Valvoline, SK, Fuchs, Sunoco, Advanced Lubrication Specialties, Rugged, Warren, Cenex, Purus, Ravenol, Kendall, BASF, Klondike, Total Energy, Petronas, Phillips 66 and Mobil.

The “Off-Highway” and heavy-duty “On-Highway” applications have also undergone some changes. The off-highway applications such as dump trucks and other heavy equipment, as well as on-highway applications such as semi-trucks and buses, use the following fluids:

  • TES 439: A mineral-based fluid, TES 439 utilizes industry-standard recommendations for fluid change intervals.
  • TES 353: A synthetic fluid with extended drain intervals and enhanced temperature stability and performance. Recommended for the 5000, 6000, 8000, and 9000 series units. Currently, Castrol is the only licensed supplier for this fluid sold under the TES 353 TranSynd name.

At this point, you are probably wondering how do I know if the fluid I am using meets the TES requirements. Simply look at the back of your fluid container (figure 1). The TES fluid certification is listed there. If nothing is listed, either do not use that fluid or contact the company to see if their fluid meets the specifications.

Well, there you have it. You are now up to date on the various Allison fluids available. Thanks again to the Allison engineering staff for their help with the information contained in this article.

Until next time remember, “Not getting what you want is sometimes a wonderful stroke of luck.”

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