Reconditioned Ford C-Max Gearbox

Which engine code determines the gearbox on a Ford C-Max?

On the Ford C-Max, it is the engine code — not simply the engine capacity — that identifies the compatible gearbox. The 1.6 TDCi, the most common engine in the range, covers several codes on its own: G8DA, HHDA, T1DA, T3DA take a 5-speed manual gearbox, whereas HWDA, HXDA, SIDA are paired with a 6-speed manual. Mixing up the two families will result in an incompatible part, even if the quoted power output is identical.

Diesel: from G8DA to XWDD – the key references to know

The 1.5 TDCi, introduced later (codes XWDA, XWDB, XWDC, XWDD), takes exclusively a 6-speed gearbox and shares no gearbox with the 1.6 TDCi despite a similar engine capacity. The 1.8 petrol (codes QQDA, QQDB) retains a 5-speed manual, fitted to first-generation C-Max models (from 2003 onwards). The 1.6 TDCi is also the engine most associated with synchromesh wear, particularly on 2nd and 3rd gear changes at higher mileages.

Petrol: 1.6, 1.6 EcoBoost and 1.0 EcoBoost

On the petrol side, the naturally aspirated 1.6 (JQDA, JQDB), the 1.6 EcoBoost (SFJA, SFJB) and the 1.0 EcoBoost (M1DA, M2DA, M1DD) all come with a 6-speed gearbox, but their casings, shafts and gear ratios differ according to the torque transmitted. The 1.0 EcoBoost in particular, despite its small engine capacity, requires a gearbox sized to handle the high torque of this three-cylinder turbo engine. Checking the engine code stamped on the block therefore remains the only reliable method before placing any order, across a production run spanning 2003 to 2019.