Jaguar Mark X / 420 (EU)

Manual transmission fluid capacity & service interval

Jaguar Mark X / 420 (EU) manual transmission fluid capacity ranges from 1,4 to 2,3 liters. Service intervals include checks at 4000, 4500, and 5000 km, with fluid changes at 16000, 18000, and 20000 km. The data covers 6 configurations.

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

TypeSpecifications
420G (1966-1970)
  • Use: Normal
  • Capacity 1,4 liter
  • Check 5000 km
  • Change 20000 km
  • Code: 4/1
  • 420G (1966-1970)
  • With overdrive
  • Use: Normal
  • Capacity 2,3 liter
  • Check 5000 km
  • Change 20000 km
  • Code: 4/1
Mark X 4.2 (1964-1966)
  • Use: Normal
  • Capacity 1,5 liter
  • Check 4500 km
  • Change 18000 km
  • Code: 4/1
  • Mark X 4.2 (1964-1966)
  • With overdrive
  • Use: Normal
  • Capacity 2,3 liter
  • Check 4500 km
  • Change 18000 km
  • Code: 4/1
Mark X 3.8 (1961-1965)
  • Use: Normal
  • Capacity 1,5 liter
  • Check 4000 km
  • Change 16000 km
  • Code: 4/1
  • Mark X 3.8 (1961-1965)
  • With overdrive
  • Use: Normal
  • Capacity 2,3 liter
  • Check 4000 km
  • Change 16000 km
  • Code: 4/1

Additional Notes

  • The Jaguar Mark X / 420 (EU) manual transmission fluid capacity varies between 1.4 and 1.5 liters depending on the variant, with the 420G (1966-1970) holding the smallest standard figure at 1.4 liters and both Mark X variants holding 1.5 liters.
  • When an overdrive unit is fitted, the fluid capacity rises to 2.3 liters across all three variants — the 420G, Mark X 3.8, and Mark X 4.2 — reflecting the additional fluid volume the overdrive housing requires.
  • The Mark X 3.8 (1961-1965) carries the shortest check interval of the group at 4000 km under normal use conditions, paired with a 16000 km change interval for the manual transmission.
  • The Mark X 4.2 (1964-1966) specifies a 4500 km check interval and an 18000 km change interval under normal use, values that sit between those of the Mark X 3.8 and the 420G.
  • The 420G (1966-1970) has the longest check interval at 5000 km and the longest change interval at 20000 km under normal use conditions, applying equally to both the standard manual and the overdrive-equipped configuration.
  • The overdrive-equipped versions of the Mark X 3.8 and Mark X 4.2 share identical check and change intervals with their respective standard manual counterparts, meaning the addition of the overdrive unit affects only the fluid capacity, not the service schedule.
  • Across the three variants, the change interval progresses from 16000 km on the Mark X 3.8 to 18000 km on the Mark X 4.2 and then to 20000 km on the 420G, a pattern that corresponds to the chronological order of the model introductions.

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