The Mercedes 7-speed transmission was shipped in the majority of models from 2004 through 2016. By 2010, the 722.9 was offered in all models, excluding those with the V12 twin-turbo models (S600, S65 AMG, SL600. SL65 AMG). Since the 7G-TRONIC (722.9) transmission is so common, these service tips apply to a wide array of vehicles.
To get the longest service life out of the 722.9 transmission, periodic maintenance is mandatory. In addition to the standard fluid service, there are modifications that you can perform during regular maintenance that can help extend the life of your transmission. Throughout the production cycle of the 722.9, Mercedes made a number of changes, including oil pan design, filter design, and updated torque converter designs. This article covers a few quick and easy modifications that you can perform to extend the service life.
Mercedes Vehicles Equipped With The 722.9 Transmission
We recommend servicing your 7G-TRONIC transmission fluid (red in color) every 30,000 miles and 7G-TRONIC PLUS transmission fluid (blue in color) every 77,000 miles. If your vehicle requires blue fluid, it will likely be 2011 or newer—you can tell by the option code 'A89'. The blue fluid is the lowest viscosity fluid offered on the 722.9 transmission and is not backward compatible with red fluid. If you mistakenly add the wrong fluid, simply drain it out and replace it with the correct fluid.
You should be periodically checking for leaks and addressing them immediately, should you find any. Transmissions operating at an incorrect fluid level, be it over-filled or under-filled, will develop running issues that will reduce its lifespan. 7G-TRONIC 4Matic transmissions are prone to leaking at the rear so be sure to pay particular attention to this area during your visual inspections.
The rear of the transmission doubles as the transfer case, and in the event of a transfer case failure, it's not sold separately. With this, the transmission shares it’s fluid with the transfer case. When servicing the transmission, drain the oil in the transfer case and check for debris—early C Class (W204) and S Class (W221) 4Matic models had tapered roller bearings in the transfer case that would develop pitting and produce noise at all speeds.
If you're looking to do a transmission fluid service, here is an incredibly helpful video walking you through the service.
The best filter you can run in the 722.9 transmission is the Filtran Smart Media triple filter that was first introduced on the 7G-TRONIC PLUS. Aftermarket filters typically contain a single layer of coarse filter media and filter down to 80um particle size. Filtran’s media filters can filter down to 50um particle size. An additional benefit of using the updated filter is if you replace a damaged component in the transmission and you find significant debris in the pan, you will no longer need to replace the entire transmission. You can simply replace the component, clean the valves, and perform a fluid and filter change.
To install the latest filter in 7G-TRONIC transmissions, you will need to upgrade to the deeper transmission pan from the 2012 and later 7G-TRONIC PLUS models. An added benefit of installing the updated components is the additional fluid holding capacity of the newer pan. We sell a convenient transmission oil pan upgrade kit.
On the 7G-TRONIC PLUS transmissions, we recommend running the latest version of the ultra-low viscosity fluid by Mercedes (gold in color). Unfortunately, this fluid is not compatible with the earlier 7G-TRONIC transmissions (red colored fluid) but is fully compatible with the PLUS transmissions that use the blue colored fluid.
Kyle is the Mercedes Catalog Manager at FCP Euro and has been with the company since 2014.