BMW 7 series, E23 (USA)

Automatic transmission fluid capacity & service interval

BMW 7 series, E23 (USA) automatic transmission fluid capacity ranges from 2 to 8,1 liters. The data covers 5 configurations.

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

TypeSpecifications
735i (1986-1987)
  • Use: Normal
  • Capacity 6,85-7,25 liter (Initial fill)
  • Capacity 2-2,4 liter (Service fill)
  • Code: ZF 3HP22 3/1
735i (1986-1987)
  • Use: Normal
  • Capacity 7,5-8,1 liter (Initial fill)
  • Capacity 3 liter (Service fill)
  • Code: ZF 4HP22/EH 4/1
735i (1984-1986)
  • Use: Normal
  • Capacity 6,85-7,25 liter (Initial fill)
  • Capacity 2-2,4 liter (Service fill)
  • Code: ZF 3HP22 3/1
735i (1984-1986)
  • Use: Normal
  • Capacity 7,5-8,1 liter (Initial fill)
  • Capacity 3 liter (Service fill)
  • Code: ZF 4HP22/EH 4/1
733i (1977-1984)
  • Use: Normal
  • Capacity 2-2,4 liter (Change capacity)
  • Capacity 6,9-7,3 liter (Dry fill)
  • Code: ZF 3HP22 3/1

Additional Notes

  • The BMW 7 Series E23 (USA) automatic transmission specifications use two distinct capacity labels across the lineup: change capacity (or service fill) and dry fill (or initial fill). The lower figure in each case represents how much fluid is needed during a routine service, while the higher figure reflects the total system volume when filling from empty.
  • The 733i (1977-1984) lists a dry fill capacity of 6.9-7.3 liters, which represents the full transmission volume including the torque converter and all internal passages when the unit is completely drained or rebuilt.
  • The 733i change capacity of 2-2.4 liters is notably lower than the dry fill, reflecting that a standard service drain does not evacuate the torque converter, leaving a significant portion of the old fluid in the system.
  • The 735i (1984-1986) appears with two separate specification rows, indicating two different automatic transmission variants were fitted to the same model year range, each with its own distinct capacity profile.
  • One 735i (1984-1986) transmission variant carries an initial fill of 6.85-7.25 liters and a service fill of 2-2.4 liters, figures that align closely with the 733i dry fill and change capacity values.
  • The second 735i (1984-1986) transmission variant has a noticeably larger initial fill of 7.5-8.1 liters and a service fill of 3 liters, both of which are higher than the first variant, pointing to a physically larger transmission unit.
  • The 735i (1986-1987) carries the same two transmission variants and identical capacity figures as the 1984-1986 735i, with one variant at 6.85-7.25 liters initial fill and 2-2.4 liters service fill, and the other at 7.5-8.1 liters initial fill and 3 liters service fill.
  • All rows across the E23 USA lineup are designated for normal use conditions, meaning none of the listed capacities or service intervals are adjusted for severe-duty driving cycles such as towing, frequent short trips, or extreme temperatures.

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