What type of lube is used on the transfer case of the specified vehicle models?

The transfer case of the specified HMMWV models utilizes Dexron 6 fluid as its lubricant. Dexron 6 is a more advanced transmission fluid that offers improved performance and protection compared to earlier formulations. It has a higher viscosity index, better thermal stability, and improved oxidation resistance. These qualities are essential for the demanding conditions faced by military vehicles like the HMMWV, which requires reliable and efficient transmission operation in various environments.

Using Dexron 6 ensures the effective lubrication of gears and smooth operation within the transfer case, which is critical for transferring power from the engine to the wheels and managing the vehicle's four-wheel drive functions. This type of fluid also minimizes wear on components, promoting longevity and reducing maintenance needs, which is paramount in military operations.

Other lubricant options like SAE 30 and manual transmission fluid do not provide the necessary properties required for optimal performance in the HMMWV's transfer case. Similarly, while Dexron 3 was previously used, Dexron 6 encompasses advancements that enhance protection and efficiency, making it the preferred choice for these specific vehicle models.