The Mercedes-Benz 5G-Tronic automatic transmission, also known as a 722.6 transmission, is an electronically shifted 5-speed automatic transmission. It is fitted to a number of vehicles within the Mercedes-Benz range, as well as some Jeep, Jaguar, and Ssangyong models. Below are some of the common faults we’ve experienced on this transmission. See the bottom of the page for a list of vehicles this transmission is fitted in.
The seals around the connector harness of the 722.6 automatic transmission are prone to flattening, allowing oil to leak out around the plug. The fix for the leak itself is relatively simple, requiring a replacement harness. If you notice your 722.6 automatic transmission leaking, be sure to have the leak repaired as soon as possible; the leaking oil can ingress up the wiring harness and damage the TCU (transmission control unit), potentially causing more damage to the transmission itself.
Faulty Electrics Pack
The 722.6 automatic transmission contains an electrics pack, also referred to as a conductor plate, which carries the electrical signals between the internal transmission components and the TCU (transmission control unit). When this plate fails, the vehicle will like go into failsafe mode and putting up fault codes relating to sensors and/or solenoids. Replacement electrics packs can be fitted.
Torque Converter Lockup Valve
The valve that controls the torque converter lockup in the 722.6 automatic transmission is prone to wear, and will eventually cause a judder during driving. The valve itself can be reamed and replaced, fixing the problem. In some cases, a replacement torque converter may also need to be fitted.
Wear and Tear
The biggest problem faced by owners of a vehicle running a 722.6 automatic transmission is that of wear and tear. 722.6 transmissions are prone to slipping, even loss of drive from general wear and tear of the internal seals and clutch packs. This usually occurs when the transmission has run somewhere in the region of 80,000 miles since new (or since the last time it was overhauled), and will require a full overhaul to repair.
On vehicles where the transmission cooler is built into the standard engine radiator, it is quite common for the pipes to corrode, allowing engine coolant to contaminate the transmission fluid. The ingredients of the engine coolant break down essential materials inside the transmission, exponentially accelerating wear of the clutches and causing the transmission to fail. In such cases, the transmission will need to be fully overhauled to remove all traces of engine coolant, and a new/auxiliary transmission cooler will need to be fitted to the vehicle.
If you have a vehicle with a 722.6 automatic transmission, it may be worth considering having an auxiliary transmission cooler fitted regardless of whether there has been water contamination or not.
Vehicles Running the 722.6 Mercedes-Benz 5G-Tronic Automatic Transmission
This list should be used as a guide only, there may be exceptions (cross-over models, for example) where a vehicle on this list is not running a 722.6 automatic transmission, and there may be vehicles not on the list that are.
- 1996–1999 Mercedes-Benz W140
- 2000-2005 Mercedes-Benz W220
- 2006–2013 Mercedes-Benz W221 (V12 Models only)
- 1997-2002 Mercedes-Benz W210
- 2003-2009 Mercedes-Benz W211 (4Matic and e320 models only)
- 1997-2000 Mercedes-Benz W202
- 2000-2004 Mercedes-Benz W203
- 1998-2005 Mercedes-Benz W163
- 1997-2004 Mercedes-Benz W168
- 2004–Present Mercedes-Benz W169
- 2005–Present Mercedes-Benz B-Class
- 1998-2005 Mercedes-Benz R170
- 1996-2002 Mercedes-Benz R129
- 2001–Present Mercedes-Benz R230 (V12 Model and Earlier, up to 2005)
- 1998-2002 Mercedes-Benz W208
- 2003-2005 Mercedes-Benz W209
- 2000-2006 Mercedes-Benz C215 (V12 Models only)
- 2007–Present Mercedes-Benz C216 (V12 Models only)
- 1996–Present Mercedes-Benz W463 (AMG Models only)
- 2005-2009 Mercedes-Benz SLR
- 2005-2012 Jeep Grand Cherokee (V6 Models only)
- 2011-Present Jeep Wrangler
- 2002–2013 Maybach 57 and 62
- 1998-2002 Jaguar X308 (Supercharged models only)
- 1998-2002 Jaguar XK (X100) (Supercharged models only)
- 2004–Present Ssangyong Rexton
- 2006–Present Ssangyong Kyron
- 2005–Present Ssangyong Rodius