International Harvester 55 / 56

Differential fluid capacity & service interval

International Harvester 55 / 56 uses differential fluid with a capacity range of 5,25 to 7 liters. Service intervals include checking at 200 hours and changing at 800 or 1000 hours. The data covers 9 configurations.

The configuration chart below lists fill volumes and service intervals for each engine and trim variant.

TypeSpecifications
  • 856 XL, 856 XLA (1984-1985)
  • Front
  • Use: Normal
  • Capacity 5,25 liter
  • Check 200 hours
  • Change 800 hours
  • 1056, 1056 XL (1982-1985)
  • Front
  • Use: Normal
  • Capacity 6 liter
  • Check 200 hours
  • Change 800 hours
  • 956, 956 XL (1982-1985)
  • Front
  • Use: Normal
  • Capacity 6 liter
  • Check 200 hours
  • Change 800 hours
  • 1255 XL (1981-1985)
  • Front
  • Use: Normal
  • Capacity 7 liter
  • Check 200 hours
  • Change 800 hours
  • 1455 XL (1981-1985)
  • Front
  • Use: Normal
  • Capacity 7 liter
  • Check 200 hours
  • Change 800 hours
  • 1055 (1978-1981)
  • Front
  • Use: Normal
  • Capacity 7 liter
  • Check 200 hours
  • Change 800 hours
  • 1255 (1978-1981)
  • Front
  • Use: Normal
  • Capacity 7 liter
  • Check 200 hours
  • Change 1000 hours
  • 1455 (1978-1981)
  • Front
  • Use: Normal
  • Capacity 7 liter
  • Check 200 hours
  • Change 1000 hours
  • 955 (1978-1981)
  • Front
  • Use: Normal
  • Capacity 7 liter
  • Check 200 hours
  • Change 800 hours

Additional Notes

  • The International Harvester 55/56 series front differential capacities across all listed configurations range from 5.25 liters to 7 liters, reflecting differences in axle housing size between the smaller and larger models in the lineup.
  • The 856 XL and 856 XLA (1984-1985) carry the smallest front differential capacity in the group at 5.25 liters, distinguishing the lower-tier model from the mid- and upper-range configurations that hold 6 or 7 liters.
  • The 1056 and 1056 XL (1982-1985) and the 956 and 956 XL (1982-1985) both specify a 6-liter front differential capacity, one liter less than the 7-liter figure associated with the 1055 and 955 models from the 1978-1981 period.
  • All nine configurations share an identical fluid check interval of 200 operating hours under normal use conditions, indicating a uniform inspection frequency regardless of model or capacity differences.
  • The 1255 (1978-1981) and 1455 (1978-1981) both specify a 1000-hour change interval under normal use, which is longer than the 800-hour change interval applied to all other configurations in the dataset.
  • When the 1255 XL and 1455 XL variants replaced the non-XL 1255 and 1455 from 1981 onward, the change interval was reduced from 1000 hours to 800 hours, despite the front differential capacity remaining at 7 liters across both generations.
  • The 7-liter capacity appears across the widest range of configurations, covering the 1055, 1255, 1255 XL, 1455, 1455 XL, and 955 models, making it the most common front differential fill volume in the 55/56 series specifications listed here.

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