Optimum performance and reliability of heavy-duty automatic transmissions can be noticeably influenced by the type of fluid used and the frequency with which that fluid is changed. Allison Transmission has designed extensive programs including specifications and tests to verify the quality of fluids and consequently have specific fluid and filter change recommendations. Due to field studies, changes in emission requirements, vehicle design, and operating environments, Allison Transmission has realigned recommended fluid and filter change intervals. Heavy-duty Automatic Transmission change intervals have been revised to more closely match today’s operating environments. In addition, GM has replaced DEXRON®-III with DEXRON®-VI effective January 1, 2007. Allison has made changes to 1000, 2000, 3000, 4000 Product Families transmissions to be compatible with DEXRON®-VI. Allison has also created a new automatic transmission fluid specification, Schedule One TES 389. The new Allison specification gives OEMs and customers another approved fluid choice.

Allison C4 fluids are no longer approved for Commercial On-Highway products

Southwest Research Institute C4 Approval Database
C4 Approved Fluid Listing

To obtain an application for a C4 qualification of a fluid, click below
C4 Application Form