Mercedes Gear Box Problems


This is a very common fault for Mercedes vehicles fitted with the 7G-Tronic automatic transmission with gearbox code – 722.9, often causing the transmission to hold too long in one gear before aggressively forcing the next gear into place, this causes a very rough and jerky gear change.

The fault usually starts out as intermittent but always becomes permanent if left unresolved for long enough. The fault is caused by the TCM conductor plate breaking down internally, preventing the control module/conductor plate from monitoring the correct rotational speed of the input shaft, making it unable to determine the slippage of the torque converter, causing ineffective torque clutch lock-up that prevents a smooth gear change or in some cases prevents gear selection entirely.

This 7G-Tronic (722.9) control module is a common failure for the following 7 speed vehicles:

C-Class – C200, C220, C230, C250, C280, C320, C350, C63 AMG

CL-Class – CL500

CLK-Class – CLK280, CLK320, CLK350

CLS-Class – CLS320, CLS350, CLS500, CLS63 AMG

SLK-Class – SLK280, SLK350

E-Class – E200, E220, E280, E320, E350, E500, E63 AMG

GL-Class – GL320, GL420

CLK-Class – GLK220

ML-Class – ML280, ML320, ML350, ML420, ML500

R-Class – R280, R320, R350

S-Class – S320, S350, S430, S500

SL-Class – SL350, SL500

SLK-Class – SLK250, SLK280, SLK350

We are Mercedes Specialists in Essex and use manufacture software so we can diagnose and repair these faults.

Contact us with any questions today.