Austin A90, BS4
Differential fluid capacity & service interval
Austin A90 and BS4 models require 1,7 liters of differential fluid. Service intervals include a check at 1500 km and a change at 9000 km. The data covers 1 configuration.
The configuration chart below lists fill volumes and service intervals for each engine and trim variant.
| Type | Specifications |
|---|---|
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Additional Notes
- The rear differential on the A90 Six Westminster carries a fluid capacity of 1.7 liters, which is consistent with a service fill volume for a rear axle housing of that era rather than a full overhaul drain-and-refill figure.
- A check interval of 1,500 km is specified under normal use conditions, reflecting a relatively short inspection cycle that keeps fluid level and condition under close observation between full changes.
- The change interval is set at 9,000 km under normal use, meaning the full fluid replacement cycle is six times longer than the check interval, spacing out the more involved service task while maintaining frequent monitoring.
- The Austin A90 Six Westminster (1954-1956) carries a single differential fluid specification with no variation across sub-trims or engine variants for the rear axle, as only one configuration appears in the available data for those model years.