Hyundai D6KF1 (6DCT)

Hyundai's dry six-speed dual-clutch — in the Elantra, Kona and Tucson, and the Kia Niro.

It is the seven-speed's smaller sibling and shares its defining weakness. The clutches run in air rather than oil, so the gearbox is at its least happy exactly where a torque-converter automatic is most comfortable — creeping in traffic, and holding station on a hill.

On the hybrid Niro it is worth knowing which symptom belongs to which system. A hesitation or a shunt from rest can be the clutch, or it can be the transition between electric and engine drive — they feel similar and they are unrelated, and a scan that shows no transmission fault has not exonerated the clutch.

Holding the car on an incline with the throttle is what wears these clutches, because the transmission answers by slipping against the whole weight of the car with nowhere to put the heat. A judder is the last stage, not the first.

A clutch actuator fault presents completely differently — a refused gear, a limp mode, a warning light, and no judder at all. Two repairs, and the tell is whether pulling away was ever wrong.