The Mercedes 722.6 5-speed automatic transmission, also known as the 5G-Tronic or NAG1, was produced from 1995 to 2014 and was installed in virtually all Mercedes-Benz models, as well as Chrysler, Dodge, Jeep, Jaguar, Porsche. Six versions of this automatic transmission were available: W5A280, W5A300, W5A330, W5A400, W5A580, W5A900. The 5G-Tronic family also includes the 722.5 and 722.7.
In 1995, a new 5-speed automatic transmission was introduced on the high-performance versions of the CL coupe and SL roadster. It differed from the old 722.5 transmission by incorporating an electronic control unit and a torque converter lockup. Its design was typical of the longitudinally mounted automatic transmission of the time: it had three planetary gear sets, three disc brakes, three locking clutches, and two overrunning clutches. Among the automatic transmission’s features, we note the presence of two reverse gears for a comfortable ride.
All transmission versions are divided into six families, each consisting of dozens of modifications:
- W5A280: commercial vehicles, minibuses, or minivans;
- W5A300: crossovers or SUVs with up to 6-cylinder engines;
- W5A330: passenger car models with up to 6-cylinder engines;
- W5A400: crossovers and SUVs with more than 6-cylinder engines;
- W5A580: passenger car models with more than 6-cylinder engines;
- W5A900: high-performance AMG versions with 12-cylinder engines.
Small NAG: W5A280, W5A300, W5A330.
Large NAG: W5A400, W5A580.
AMG modifications: W5A900.
Specifications
| Type | automatic transmission |
| Number of gears | 5 |
| Type of drive | rear / all wheel |
| Engine volume, l | up to 3.3 (Small NAG) up to 5.5 (Large NAG) up to 6.2 (AMG modifications) |
| Torque output, Nm | up to 350 (Small NAG) up to 600 (Large NAG) up to 1000 (AMG modifications) |
| Recommended oil | ATF MB 236.14 |
| Oil capacity, liter | 7.0 – 8.0 (Small NAG) 7.8 – 9.2 (Large NAG) 8.5 – 9.5 (AMG modifications) |
| Partial replacement, liter | 5.0 – 6.0 (Small NAG) 5.8 – 7.2 (Large NAG) 6.5 – 7.5 (AMG modifications) |
| Maintenance | every 60 000 km |
| Gearbox lifespan, km | ~500 000 km (Small NAG) ~400 000 km (Large NAG) ~300 000 km (AMG modifications) |
| Weight, kg | 76 |
Gear ratios Mercedes 722.6
Using the example of a 1999 Mercedes E430 with a 4.3 liter engine:
| Main | 2.82 |
| 1st | 3.595 |
| 2nd | 2.186 |
| 3rd | 1.405 |
| 4th | 1.000 |
| 5th | 0.831 |
| Reverse | 3.167 |
Using
The transmission was installed on:
- Chrysler 300C 1 (LX) in 2004 – 2010; 300C 2 (LD) in 2010 – 2014;
- Chrysler Crossfire 1 (ZH) in 2003 – 2007;
- Dodge Charger 1 (LX) in 2005 – 2010; Charger 2 (LD) in 2010 – 2020;
- Dodge Challenger 3 (LC) in 2008 – 2014;
- Dodge Durango 3 (WD) in 2010 – 2014;
- Dodge Magnum 1 (LE) in 2004 – 2008;
- Dodge Nitro 1 (KA) in 2006 – 2011;
- Jaguar XJ 6 (X308) in 1998 – 2003;
- Jaguar XK 1 (X100) in 1998 – 2002;
- Jeep Commander 1 (XK) in 2005 – 2010;
- Jeep Cherokee 4 (KK) in 2007 – 2012;
- Jeep Grand Cherokee 3 (WK) in 2004 – 2010; Grand Cherokee 4 (WK2) in 2010 – 2013;
- Jeep Wrangler 3 (JK) in 2011 – 2018;
- Lancia Thema II (LD) in 2011 – 2014;
- Maybach 57 W240 in 2002 – 2013;
- Maybach 62 V240 in 2002 – 2013;
- Mercedes C-Class W202 in 1996 – 2001; C-Class W203 in 2000 – 2007; C-Class W204 in 2007 – 2011;
- Mercedes CL-Class C140 in 1995 – 1998; CL-Class C215 in 1999 – 2006; CL-Class C216 in 2006 – 2013;
- Mercedes CLK-Class C208 in 1997 – 2003; CLK-Class C209 in 2002 – 2009;
- Mercedes CLS-Class C219 in 2004 – 2006;
- Mercedes E-Class W210 in 1996 – 2002; E-Class W211 in 2002 – 2009; E-Class W212 in 2009 – 2013;
- Mercedes G-Class W463 in 1996 – 2012;
- Mercedes ML-Class W163 in 1997 – 2005;
- Mercedes S-Class W140 in 1996 – 1998; S-Class W220 in 1998 – 2005; S-Class W221 in 2006 – 2013;
- Mercedes SLR-Class C199 in 2003 – 2010;
- Mercedes SL-Class R129 in 1995 – 2001; SL-Class R230 in 2001 – 2011;
- Mercedes SLK-Class R170 in 1996 – 2004; SLK-Class R171 in 2004 – 2011;
- Mercedes Sprinter W901 in 2000 – 2006; Sprinter W906 in 2006 – 2013;
- Mercedes Viano W639 in 2003 – 2014;
- Mercedes Vito W639 in 2003 – 2014;
- Porsche 911 V (996) in 2000 – 2006; 911 VI (997) in 2006 – 2010;
- SsangYong Actyon Sports 1 (Q100) in 2012 – 2016;
- SsangYong Chairman 1 (W100) in 1997 – 2014;
- SsangYong Kyron 1 (D100) in 2005 – 2015;
- SsangYong Rexton 1 (Y200) in 2003 – 2015;
- SsangYong Rodius 1 (A100) in 2004 – 2013; Rodius 2 (A150) in 2013 – 2015.
Disadvantages of the Mercedes 722.6 gearbox
- In its early years, this transmission had numerous flaws, earning it a bad reputation: the planetary bearings, the turbine shaft, the sliding bushing at the input-output shaft junction, and the K1 freewheel clutch wore out very quickly. Between 1998 and 2001, the design was refined, and the transmission’s reliability improved significantly.
- Until approximately 2003, many Mercedes models were equipped with defective radiators, which allowed antifreeze to enter the oil, significantly reducing the transmission’s service life. After 2003, the problem persisted, and complaints about it continue to be heard.
- The designers placed the transmission’s electronic control unit inside the transmission, and if its contacts become unsealed, oil would leak in and disable the ECU. Leaks in the contact connector bushing are also common, and the transmission may run dry.
- All other problems with this automatic transmission are related to contamination by wear debris. The torque converter lockup clutch gradually deteriorates, and this debris then clogs the solenoids and channels in the valve body, causing the automatic transmission to jolt when shifting.
