Unimog (MB) 421

Manual transmission fluid capacity & service interval

Unimog (MB) 421 manual transmission fluid capacity is 6 liters. Service intervals include checks at 800 hours and changes at 1600 hours or 12 months. The data covers 1 configuration.

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

TypeSpecifications
U 600, U 600 L (421) (1970-1992)
  • Use: Normal
  • Capacity 6 liter
  • Check 800 hours
  • Change 1600 hours/ 12 months
  • Code: 20/8

Additional Notes

  • The U 600 and U 600 L carry a manual transmission fluid capacity of 6 liters, a figure consistent with a service fill rather than a full overhaul drain, where residual fluid typically remains in galleries and passages.
  • The check interval for manual transmission fluid is set at 800 hours of operation, reflecting the hour-based service scheduling common to commercial and utility vehicles that accumulate running time rather than road distance.
  • The change interval is defined as 1,600 hours or 12 months, whichever comes first, meaning calendar time places an upper boundary on fluid life independent of actual operating hours logged.
  • Both the check and change intervals apply under normal use conditions, which in heavy-duty utility vehicle service typically represents standard working loads rather than sustained extreme duty cycles.
  • The Unimog (MB) 421 spans a production window from 1970 to 1992, and the single set of transmission fluid specifications applies uniformly across the entire 22-year range without variation by sub-year or variant.

Other Systems