2019 International LT Transmission Fluid & Service

Quick answer

• Transmission make/model: Eaton Endurant
• OEM fluid spec: Eaton PS-386 (or equivalent synthetic 50-weight oil)
• Drain & fill capacity: approximately 16 pints (2 gallons / 7.6 liters)
• Full overhaul capacity: not applicable (see service procedure)
• Filter OEM part number: K-4360
• Recommended service interval: 500,000 miles (800,000 km) or 5 years

Fluid type explained

The Eaton Endurant transmission is specified with Eaton PS-386 synthetic transmission fluid. This is a 50-weight synthetic oil designed for high-efficiency, long-haul applications. It provides excellent thermal stability, shear stability, and protection for the gears and bearings. Always use a fluid that meets the PS-386 specification to ensure proper performance and to avoid voiding the warranty.

Service procedure

The Eaton Endurant has a single service procedure for fluid and filter changes. There is no distinction between a "drain and fill" and a "full exchange" as there might be in a passenger car automatic transmission with a torque converter. The procedure involves draining the fluid, removing the cooler and filter module, replacing the filter, reinstalling the module, and refilling with fresh fluid. This procedure replaces all of the transmission's fluid.

Service interval

The recommended service interval for the Eaton Endurant transmission is 500,000 miles (800,000 km) or 5 years, whichever comes first. This is considered a "severe duty" interval, as it is designed for the typical long-haul use of a Class 8 truck. There is no "normal duty" interval.

Common transmission problems

The Eaton Endurant is a robust and reliable transmission, but some common issues have been reported. These include:

• Mechatronic failures: The Endurant is an automated manual transmission, and the electronic and hydraulic components that control shifting can sometimes fail. This can lead to a variety of symptoms, including harsh shifting, slipping, or a complete loss of drive.
• Clutch issues: While the Endurant is an automated manual, it still has a clutch. Clutch wear and failure can occur, especially in high-mileage or heavy-haul applications. Symptoms include slipping, chattering, or a failure to engage.
• Software glitches: Like any modern electronic system, the Endurant's software can sometimes have glitches. This can cause a variety of shifting and performance problems. Updating the software can often resolve these issues.

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