MG MGB / MGC

Manual transmission fluid capacity & service interval

MG MGB / MGC manual transmission fluid capacity ranges from 0,4 to 3,4 liters. Service intervals include checks every 10000 km or 6 months and changes every 40000 km or 24 months. The data covers 6 configurations.

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

TypeSpecifications
MGB (1974-1980)
  • Use: Normal
  • Capacity 2,8-3,4 liter
  • Code: 4/1
MGB (USA/CAN) (1974-1980)
  • Use: Normal
  • Capacity 2,8-3,4 liter
  • Code: 4/1
MGB GT V8 (1973-1976)
  • Use: Normal
  • Capacity 3,4 liter
  • Check 10000 km/ 6 months
  • Change 40000 km/ 24 months
  • Code: 4/1
MGC (1967-1969)
  • Use: Normal
  • Capacity 3 liter
  • Capacity 0,4 liter (Overdrive unit)
  • Code: 4/1
MGB GT (1965-1974)
  • Use: Normal
  • Capacity 2,6 liter
  • Code: 4/1
MGB (1962-1974)
  • Use: Normal
  • Capacity 2,6 liter
  • Code: 4/1

Additional Notes

  • The MGB (1962-1974) and MGB GT (1965-1974) share a manual transmission fluid capacity of 2.6 liters, a figure consistent with the smaller, four-cylinder gearbox fitted to both the roadster and fastback body variants of that era.
  • From 1974 onward, the MGB manual transmission capacity rises to a range of 2.8-3.4 liters, reflecting a revised gearbox specification. The range rather than a fixed value indicates that the correct fill level is determined by the overflow or level plug method rather than a precise measured quantity.
  • The MGB GT V8 (1973-1976) carries the highest fixed manual transmission capacity in the lineup at 3.4 liters, which aligns with the heavier-duty gearbox required to handle the torque output of the Rover V8 engine.
  • Among all configurations listed, the MGB GT V8 is the only one with explicit service interval data. A fluid check is specified at 10,000 km or every 6 months, and a full fluid change at 40,000 km or every 24 months, both under normal use conditions.
  • The MGC (1967-1969) lists two separate capacity figures: 3.0 liters for the main gearbox and an additional 0.4 liters for the overdrive unit. The overdrive is a self-contained auxiliary gearbox section with its own fluid reservoir, requiring independent servicing.
  • The USA/CAN market MGB (1974-1980) shares the same 2.8-3.4 liter capacity range as the standard international MGB of the same years, indicating no regional difference in the gearbox specification itself for those markets.

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