Reconditioned Opel Vivaro 2.5 CDTi Gearbox

2.5 CDTi Vivaro: four G9U engine codes for a single 6-speed gearbox, but failures that arrive early

The G9U is a robust unit on paper, but the 6-speed manual gearboxes paired with it have well-documented weaknesses on the Vivaro between 2003 and 2014. The first symptom that prompts intervention isdifficulty or inability to select 3rd and 4th gear, often made worse by a clunking noise on downshifts. In heavy-load or intensive urban-cycle use — typical of a light commercial vehicle — synchromesh wear accelerates and can render the gearbox unusable in under 200,000 km. An oil leak at the sump or input shaft seal is a second frequently seen warning sign: left unattended, it hastens differential bearing failure.

Four G9U codes: what differs between G9U630, G9U632, G9U650 and G9U730

The four engine codes identified —G9U630, G9U632, G9U650 and G9U730— correspond to variants with different power and torque outputs. These differences in transmissible torque influence the internal sizing of the gearbox: a reference from a G9U630 is not necessarily suitable for a G9U730. To identify the exact reference, the engine code stamped on the block remains the determining factor, even before the year or body style of the Vivaro.