722.9, 7G-TRONIC, NAG2

The Mercedes-Benz 722.9, commonly known as 7G-TRONIC or NAG2, is a 7-speed electronically controlled automatic transmission developed for longitudinal-engine Mercedes-Benz vehicles. Introduced in the early 2000s as the successor to the 722.6 5-speed transmission, it uses a torque converter with lock-up clutch, planetary gearsets and an integrated electro-hydraulic control system. The transmission control unit and speed-sensing electronics are incorporated into the internal VGS/conductor plate assembly.

Specification: 7-speed automatic • Mercedes-Benz 722.9 • 7G-TRONIC / NAG2 • Longitudinal installation • Rear-wheel-drive and 4MATIC applications • Torque converter with electronically controlled lock-up clutch • Planetary gearsets • Electro-hydraulic valve body • Integrated VGS transmission control • Internal turbine and output speed sensors • Electronic pressure and shift control • Multiple transmission variants and torque capacities depending on vehicle and engine application.

Commonly fitted across selected Mercedes-Benz C-Class, E-Class, S-Class, CLS, CLK, SL, SLK, M/ML-Class, GL/GLK and R-Class applications, with additional variants used in other Mercedes-Benz vehicles. Numerous versions of the 722.9 were produced with different VGS generations, valve bodies, torque converters, gearsets and torque capacities, so the vehicle VIN, complete 722.9xx transmission number and component identification should always be confirmed before ordering replacement parts.

Common Faults

Common 722.9 problems include VGS/conductor plate failure, internal turbine and output speed-sensor faults, valve-body wear, pressure-control solenoid faults and torque-converter lock-up problems. Typical symptoms include harsh or delayed gear changes, transmission remaining in one gear, intermittent loss of gear selection, slipping, incorrect shifting and transmission limp mode. Internal speed-sensor failure within the conductor plate is particularly well documented on the 722.9 and can prevent the transmission controller from correctly determining transmission speed and shift operation.

Common Fault Codes