Meritor Tridem axles, RZ
Differential fluid capacity & service interval
Meritor Tridem axles, RZ use differential fluid with a capacity range of 16,3 to 26,5 liters. The data covers 3 configurations.
The configuration chart below lists fill volumes and service intervals for each engine and trim variant.
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Additional Notes
- Across the RZ-166, RZ-186, and RZ-188 configurations, Axle 3 consistently holds the smallest fluid volume of the three axles, ranging from 16.3 liters on the RZ-166 and RZ-186 to 17.1 liters on the RZ-188.
- The Meritor Tridem axles RZ series specifies differential fluid capacities per individual axle rather than as a combined system total, meaning each axle position requires a separate fill measurement during service.
- On the RZ-166, Axle 1 and Axle 2 share an identical capacity of 18.5 liters each, while Axle 3 requires 16.3 liters, bringing the total fill across all three axles to 53.3 liters.
- The RZ-186 introduces a larger Axle 1 capacity of 26.5 liters compared to the RZ-166's 18.5 liters for the same position, while Axle 2 and Axle 3 retain 18.5 liters and 16.3 liters respectively.
- On the RZ-188, both Axle 1 and Axle 2 carry 26.5 liters each, making the combined fill for just the first two axles 53.0 liters before Axle 3's 17.1 liters is added.
- The RZ-188 carries the highest total differential fluid volume of the three configurations, with all three axles summing to 70.1 liters under normal use conditions.
- All three configurations list normal as the use condition for differential fluid service, meaning the stated capacities apply to standard operating environments rather than severe-duty cycles.