The Mercedes-Benz holding company Daimler is one of the few car manufacturers who designs and manufactures their own transmissions.
For a long time, Daimler has been using numbering 722, which means automatic transmission of the car. The subsequent number in turn shows the generation. Thus, 722.1 is the automatic transmission of the first generation and 722.8 is the eighth generation aggregate.
Since the history of this car brand s very long and there are many different types of transmissions, we will give you a brief overview of the most common transmission with 5 and more gears. In addition, we also provide the recommended oil change interval and the type of oil that should be used.
722.5
5 gears, planetary transmission, rear wheel drive. In fact, a 4-speed transmission (type 722.4) with 1 additional gear planted. Used up to the end of the 90s on 5-cylinder cars.
The recommended oil change interval is 80,000 to 100,000 km.
It is recommended to use 236.10/12, but it is also permitted to use 236.1/6/7/8/81/9 certified oil.
722.6
5 gears, planetary transmission, rear- and four-wheel drive. Mercedes 5G-Tronic or NAG1. The first Mercedes full-electric 5-speed transmission with lockable hydraulic turbine was in use 1997-2009. The first variants were relatively weak, but the last copies of the series are practically bombproof.
There are almost 100 different versions of the same transmission and 100-600 hp are used (including Maybach and McLaren SLR), up to 1000 Nm are allowed. Transmission are with several different transmissions, with a very wide range of clutch discs (different variations), control unit modifications, turbine, etc. (W5A300 / W5A330 / W5A400 / W5A580 / W5A900). Also used on many Jeep, Dodge, Jaguar, Ssangyong and Porsche models.
Typical defects are planetary breakage, wear of guide bushings and sliding bearings, speed sensor errors, plugs leaks, freewheel clutches, coolant leaks. Most errors are avoided with proper transmission maintenance.
Recommended oil change interval:
1997 – 2000 models up to 80,000 km 2000 and newer up to 100,000 km AMG and other over 400 hp models up to 60,000 km
Used transmission oil brand: 236.10, 236.12 grade oils were used but now only 236.14 grade oil is used.
722.7
5 gears, front-wheel. Mercedes A-Class transmission with a relatively rare construction. Cheap to produce, expensive to keep. With several standard errors, that is why it is sensitive in driving long time with the old oil.
Recommended oil change interval up to 80,000 km. Class 236.10 oil is used.
722.8
Variable transmission (conditionally 7 gears), front-wheel drive. Mercedes Autotronic. Unit A and B installed. Manufactured in collaboration with JACTO (manufacturer of the Nissan transmission). Like all transmission, it is very sensitive to driving with old oil. The cost of repairing the chain gear is over 2500 €.
Recommended oil change interval up to 60,000 km. This is a transmission that Daimler himself gives a recommendation of up to 60,000 km, so it is worth the time. Class 236.20 oil is used.
722.9
7 gears, planetary transmission, rear and quadricycles. Mercedes 7G-Tronic or NAG2. Came to the market in 2003 and is still produced (2018). Used on vehicles with a very broad spectrum (rear wheel, hybrid, four-wheel drive, 4-wheel drive, etc.) as well as 722.6 on vehicles with different powers.
It is a transmission where the transmission control unit is inside the transmission. More economical and faster than 5-speed circuits and many details made for the first time with magnesium alloy.
In the early years, there were a number of typical defects that meant jerky gear changes and faulty control units, and so there was some disappointment that with what the Daimler immediately started to deal with.
After the changes in transmission software, replacement of oil norms and improvements in mechanics and electronics, the transmission has become quite good, but the main problems are in the control units as well as the wear of the planetarium and the turbine.
Generally very durable transmission, but needs proper maintenance to avoid mechanical faults. Also used under license on SsangYong models.
Recommended oil change interval is up to 80,000 to 120,000 km. AMG and other over 400 hp models up to 60,000 km.
236.12 was used, but now only 236.14 grade oil.
722.9 FE
7 gears, planetary transmission, rear and quadricycles. Mercedes 7G-Tronic Plus or NAG2 +. This is the development of the 722.9 transmission that was introduced to the market in 2010, mainly for fuel savings. Theoretically, approximately 7% savings are achieved, i.e. about 0.6 l per 100 km for class S.
To achieve this goal, a number of components such as gaskets, planets, oil baths, etc. were modified in the transmission mechanics. A completely new and first-rate hydraulic coupling to reduce vibration at different speeds. A special, very liquid oil (the most liquid in the world in 2010), which has been painted blue, has also been used to save fuel, so the oil pump has also to be changed. In addition, the software of the transmission has updated. From the spare part program, the transmission is recognized as a rear-wheel drive W7C700, a four-wheel drive W7X700 and a reinforced W7C1000.
NB! Be sure not to use the wrong oil or universal oil but only the original blue 236.15 grade oil. The repair of this transmission is very expensive, because the use of old oil is mainly due to the mechanical parts, which has a high cost in the dealership.
Recommended oil change from 80,000 to 120,000 km. AMG and other over 400 hp models up to 60,000 km.
Transmission oil used:use only 236.15 grade oils.
725.0
9 gears, planetary transmission, rear and quadricycles. Mercedes 9G-Tronic. The transmission was first introduced in 2013. It was the world’s first 9-speed box.
Practically in every area it is the best, starting from the cost of the production and speed, the manufacturing cost, the materials used, the weight of the aggregate to the comfort of use.
The transmission uses a very specific special oil 236.17 – for the first time this oil is made from natural gas. Use only licensed oil. Given the scarcity of this transmission on the secondary market, the huge number of gear changes and the cost of spare parts, it is highly recommended that you observe the oil change intervals.
Recommended oil change interval: up to 80,000 km. AMG and other over 400 hp models up to 60,000 km.
Used transmission oil brand: only use 236.17 grade oils.
724.0
7 gears, DCT transmission, front and four-wheel drive. Mercedes 7G-DCT. Due to new technologies, even better fuel economy than the so far economical 722.8 transmission (9% lower heating cost).
Debuted at the end of the 2011 in Mercedes B-Class and is also used in Class-A models (including AMG models). Used on smaller models of Mercedes A, B.
Recommended oil change interval: 60,000 km.
Used transmission oil brand: 236.21
