2018 Mercedes-Benz AMG GT Problems: 4 Known Issues

On the 2016-2021 Mercedes-Benz AMG GT M178 4.0L twin-turbo V8, the C190/R190 two-door AMG GT does not use a torque-converter automatic. It uses a rear-mounted Getrag/Magna 7DCL750 seven-speed dual-clutch transaxle — the same family as the Ford GT unit — and it is the single most expensive failure point on the car. Owner and specialist reports converge on a consistent set of failure modes: clutch pack wear producing shudder or hesitation on take-up, internal speed sensor failures throwing transmission control faults, oil weeping from the transaxle case weep holes, and seal/gasket leaks. Forum threads document malfunction codes tied to the electronic transmission control and DCT-specific CCP and SAP faults. The unit is intolerant of missed service: it demands strict fluid intervals and Mercedes-approved fluid, and abnormal vibration or slow engagement is the documented early warning that the gearbox is going. Because the transaxle sits at the rear of a torque tube, access is poor and labor is heavy. This is entirely distinct from the X290 four-door's front-mounted 9-speed AMG SPEEDSHIFT TCT.

On the 2016-2022 Mercedes-Benz AMG GT 4.0L V8 Biturbo M178, the C190 AMG GT mounts its rear transaxle on three ACTIVE (electronically controlled) mounts that stiffen under hard cornering and soften at idle. The most common reported failure isn't rubber breakdown — it's wiring harness or connector corrosion at the mount sensors, which trips dash warnings ("Suspension malfunction" / "Engine/transmission mount fault") and forces the mounts into a default-soft state. The fix is usually harness cleaning or connector replacement; full mount replacement is uncommon but expensive when needed (active mounts are pricey OEM parts and labor at the rear of the car is significant).

On the 2016-2018 Mercedes-Benz AMG GT M178 4.0L twin-turbo V8, on the C190/R190 two-door AMG GT, engine torque reaches the rear-mounted transaxle through a carbon-fiber torque tube driveshaft that is bonded — not bolted — to its metal end flanges. Production residue left on the bonding surfaces impaired the adhesive joint, so the bond can progressively fail and the shaft can spin free of or separate from the flange. The result is a sudden, total loss of drive with the engine still running, and in a worst case a liberated shaft inside the tunnel. Mercedes-Benz never got this right on the first attempt: NHTSA campaigns 16V308000, 19V457000 and 21V478000 all cover the same carbon-fiber driveshaft bond on overlapping 2016-2018 build windows, with the 2021 campaign covering cars built July 8, 2015 through March 22, 2017. Because the same VIN can fall under more than one campaign, an owner who had the earlier inspection done is not automatically clear of the later one. This is specific to the M178 two-door GT/GT S architecture and does not apply to the X290 four-door GT 43/53/63, which uses a conventional front-mounted 9-speed and steel/aluminum driveshaft.

On the 2016-2021 Mercedes-Benz AMG GT, the AMG GT has been recalled repeatedly across its entire production run for defects in the telematics communication module that carries the emergency call function, and the campaigns stack across different root causes rather than repeating one. NHTSA 21V058000 covers 2017-2021 AMG GT models for emergency call system software; 21V072000 covers certain 2018 AMG GT and 2020 AMG GT 53 cars whose communication module may have been deactivated during a service visit; 19V787000 covers 2016-2017 AMG GT S and 2017 AMG GT for eCall software; and 22V365000 covers 2019-2021 AMG GT models for a communication module SIM card software defect. The common consequence is that after a crash the vehicle may fail to transmit the automatic emergency call, or may transmit an incorrect vehicle location to the responder — a silent failure the owner has no way to detect, since the system gives no indication it is inoperative until it is needed. Note this is the telematics/eCall path, entirely separate from the later instrument-cluster reset recall.