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Transmission Fluids
Product Data
Castrol
®
TranSynd
®
668
November 2021
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
TM
specification differentiators such as extended anti-
shudder durability and extended clutch friction durability.
This fluid features an Allison TES 668 approval. The TES 668
TM
spec is fully backwards
compatible for both TES 295
®
and TES 468
TM
applications, but is not approved for
TC10.
Features and Benefits
Castrol TranSynd 668 delivers:
• Improved gear protection
• Extended anti-shudder and clutch-friction durability
• Excellent corrosion and foaming resistance
• Excellent thermal and oxidative stability that helps to prevent deposits and oil thickening
• Excellent transmission cleanliness under all conditions for extended oil-drain intervals and decreased servicing
• Excellent temperature reduction through reduced friction, leading to longer oil and component life
• Outstanding cold-flow properties, with faster oil flow to all critical components particularly during cold starts
• Optimized frictional characteristics for smoother gear changing at all ambient temperatures and load conditions
• Excellent shear stability properties help to retain full transmission performance over entire oil-drain interval
Castrol TranSynd 668 can deliver up to 12 times longer drain intervals than conventional and other non-Allison-
approved synthetic fluids. This can reduce costs in inventory, labor, used-oil disposal, and equipment downtime.
Industry Specifications and OEM Approvals:
• Allison TES 668
TM
(fully backwards compatible with Allison TES 295
®
and TES 468
TM
but
not approved for TC10).
TES 668
TM
builds on the demonstrated performance of the previous TES 295
®
spec in key areas such as oxidative
stability, anti-wear performance, and friction durability. The spec differentiators include improved wear protection,
extended anti-shudder durability, and extended clutch-friction durability
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