Getrag 233 / MTI550

Getrag's manual gearboxes outside the B6 and 420G — the 233 behind Supras and BMWs, the DMT6 in Chrysler's small cars, and the MTI550.

⚑ MTI550 is a torque rating in the name: 550 newton-metres. Getrag numbers this way throughout — the 420G and 560G do the same — so a number that looks like a model year is a capacity, and it is the figure that decides whether a gearbox suits a modified engine.

Getrag builds to a customer's specification, which is why the same design appears with a Getrag number, a maker's own code and an RPO code on the same car. The Getrag number is the one that finds engineering material; the others find option lists.

The 233 is the well-known one — a strong rear-drive six-speed that BMW and Toyota both used, and a common swap target for that reason.

Fluid specification is the recurring complaint across all of them: Getrag specifies its own, the interval is longer than owners expect, and a generic gear oil produces a notchy cold shift.