Automatic gearbox jerking: causes, cost and affected cars

Jerks when pulling away, harsh or delayed shifts, refusing to engage drive or reverse: these are the symptoms of an automatic gearbox in trouble. The cause and the cost depend heavily on the type of gearbox: dual-clutch, automated manual or conventional torque converter. A software update or a fluid change sometimes solves the problem; at worst, it is the whole gearbox.

Dual-clutch gearboxes (DSG, S tronic, PowerShift, DCT)

These are the most often cited for jerking, especially at low speed and from cold:

• Ford PowerShift: jerks at standstill or when pulling away, hesitation, harsh shifts, sometimes unable to engage a gear, on the B-Max, Kuga, Mondeo and Tourneo Connect (Ford B-Max guide; Ford Mondeo IV guide).
• BMW DKG7: jerks at low speed and from cold, improved by a software update that not every used car has received (Restauration automobile).
• Kia DCT7: vibrations at very low speed; Kia issued a technical note and the dual clutch may need replacing (L'argus).
• Audi S tronic: a 2009 recall reprogrammed the gearbox of Audi Q5s to improve shifts (Fiches-auto); a 2009 Q5 2.0 TDI 170 owner reports a gearbox replaced at 35,000 km (Fiches-auto).

Automated manual gearboxes (MTA, Dualogic, AMT)

An automated manual is a manual gearbox whose clutch and shifts are driven by an actuator. If the actuator, its sensor or the hydraulic pressure weakens, it jerks, refuses a gear or drops into neutral (Fiches-auto, Fiat 500; CarVerif, Abarth 500).

Conventional automatic gearboxes

Torque-converter gearboxes suffer mostly with age and tired fluid: slipping and hesitant shifts beyond 80,000 km on the Mercedes C-Class W203 (CarVerif), cold jerks on the 7G-Tronic (CarVerif, Mercedes G 320 CDI). A gearbox overhaul is priced at around €3,000 on a BMW X5 E70 (CarVerif).

"Lifetime" fluid is a false economy

Automatic gearbox fluid is often presented as lasting the life of the car. Yet wear creates metal particles that mix into the fluid; fluid that is too contaminated can damage the gearbox to the point of failure. Regular fluid changes are essential (Caradisiac). CarVerif, for example, recommends a change every 80,000 to 100,000 km on the 7G-Tronic (CarVerif).

Before buying a used car

Test the gearbox cold, in town and when manoeuvring: turn down a car that jerks repeatedly, slips, is slow to engage D or R, shows a warning or goes into limp mode (CarVerif, Audi A1 II; CarVerif, Audi Q5 II). Ask whether software updates and gearbox fluid changes have been done. See also reliable used automatic gearboxes.