McCormick X8 Series
Differential fluid capacity & service interval
McCormick X8 Series differential fluid capacity ranges from 9 to 10 liters. Service intervals consist of 250 hours or 1000 hours/12 months. The data covers 8 configurations.
The configuration chart below lists fill volumes and service intervals for each engine and trim variant.
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Additional Notes
- The McCormick X8 Series front differential holds 10 liters across the X8.660, X8.670, and X8.680 VT-Drive models covering 2017-2022, indicating a consistent service fill volume for that generation regardless of power variant.
- Stage V variants of the X8.627 and X8.631 VT-Drive introduce an axle-type distinction in front differential capacity, with a suspended front axle requiring 10 liters and a rigid axle requiring 9 liters — a 1-liter difference tied directly to axle configuration.
- The 10-liter figure across these front differentials reflects a working service fill, meaning the volume needed to bring the unit to the correct operating level during a routine fluid change rather than a full overhaul strip-down.
- Normal-use service intervals for the front differential are set at 1000 hours or 12 months, whichever comes first, across all listed configurations from both the 2017-2022 generation and the Stage V variants.
- The X8.660, X8.670, and X8.680 VT-Drive models each carry a first-change-only interval of 250 hours for the front differential. A first-change interval at 250 hours is standard practice for breaking in new gear oil that has accumulated metal particles during initial component wear-in.
- After the first-change service at 250 hours on the 2017-2022 X8.660, X8.670, and X8.680, the interval extends to 1000 hours or 12 months under normal use conditions, representing a fourfold increase in the drain period.
- The Stage V X8.627 and X8.631 specifications do not include a first-change-only interval, meaning the front differential on those configurations operates on the single 1000-hour or 12-month normal-use schedule from the outset.