Mitsubishi F4A4x (F4A42 / F4A51)

4-speed automatic · transverse · 1990–2006

Also known as: f4a42, f4a51, f4a33-1, f4a33, f5a51, mitsubishi 4-speed automatic

Mitsubishi's transverse four-speed automatic — in the Eclipse, and in the Dodge Stratus, which is the connection worth making: Chrysler and Mitsubishi built cars together for two decades, and a Stratus JR is a Mitsubishi underneath.

So a Stratus owner's transmission literature is Mitsubishi's, not Chrysler's — and this gearbox has nothing to do with the Ultradrive that the same badge carries on other models. Two Dodges of the same year can have two entirely unrelated transmissions.

Its recurring failure is the solenoid pack and the valve body, presenting as a harsh or delayed engagement into drive and a flare on the 2–3 change. It arrives gradually and is usually blamed on the clutch packs, which at that stage are typically still serviceable.

Fluid is Mitsubishi's Diamond SP-III, not a Chrysler ATF+4 and not a generic Dexron. Filling one by the badge on the boot is the mistake this page exists to prevent.

Cars fitted with this gearbox

3 generations. Only where a source names the model and the generation together — a gearbox is documented as a product far more often than as a fitment, so this list is deliberately shorter than the truth.

Information, not instruction

CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.

Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.

Community experience

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