Castrol TranSynd 668 is a premium, full-synthetic automatic transmission fluid specifically formulated for Allison Transmission on-highway automatic transmissions. TranSynd 668 provides oxidative stability, anti-wear performance, and friction durability, as well as TES 668 ...Castrol TranSynd 668 is a premium, full-synthetic automatic transmission fluid specifically formulated for Allison Transmission on-highway automatic transmissions. TranSynd 668 provides oxidative stability, anti-wear performance, and friction durability, as well as TES 668 specification differentiators such as extended anti-shudder durability and extended clutch friction durability.
This fluid features an Allison TES 668 approval. The TES 668 spec is fully backwards compatible for TES 295 applications, but is not backwards compatible for TES 468 applications.