As we’ve demonstrated on the blog, the Mercedes 722.9 or “7G-Tronic” transmission is a tough and widely found unit. With regular maintenance, they’re as reliable as they come, but the service work needs to be correct. Mercedes offered two 722.9 variants that don’t share their serviceable filter and fluid type, so you need to know which you have before buying any parts. But, as if that wasn’t enough, the changeover between variants happened abruptly in the middle of a model year. That can make differentiating the two a bit of a challenge, so we’re here to show you how you can figure all of that out yourself.
Read Our Full Guide To The Mercedes 722.9 7G-Tronic Transmission Here
Mercedes 722.9 7G-Tronic Transmission Variants
The Mercedes 722.9 automatic transmission has two versions that can be classified as “early” and “late.” In advertisements, the updated “late” 722.9 was called the “Plus” model, signifying Mercedes’ several updates. Any Mercedes with the updated 722.9 Plus gearbox will also have the A89 option code.
The “Plus” model (which can go by another name internal to Mercedes, the NAT2FE+) is effectively a redesign and improvement of the original 722.9 (internally, the NAT2). Hardware improvements include a revised torque converter using a world-first centrifugal pendulum damper—which helps longevity, cooling, and eliminating slip—an auxiliary oil pump for adequate stop/start lubrication, an operating system specifically designed around “Eco” drive modes, and transmission gearset materials designed for reduced friction. As such, the Plus offers quicker and smoother shifts as the byproduct of those hardware and software upgrades.
With those improvements, Mercedes determined a new fluid with different characteristics was needed. The early 722.9 model used a red fluid, more in line with traditional ATF. The Plus, however, used a blue fluid with much lower viscosity to help with the redesigned components aiming at reduced friction. Neither fluid is compatible with the other’s transmission, so ensure you know exactly what you need before pouring any in.
Does My Mercedes 722.9 Transmission Need Red or Blue Fluid?
There are a few ways that you can determine which fluid your Mercedes 722.9 transmission will take. What you decide to do will likely depend on how dirty you want to get.
Production Date
By common nomenclature and the color of the fluid, earlier 722.9 transmission models will use Red fluid, while late-production 722.9 “Plus” models are the ones that require blue fluid. This age distinction is why Mercedes owners will generally find kits that include red fluid for servicing labeled as “Early” service kits and kits with blue fluid labeled as “Late” service kits.
As we noted in our comprehensive 722.9 Guide, 722.9 “Plus” models using the blue fluid began production on 06/21/2010; this means that all vehicles sold stateside with a 2012 model year and later sporting the 722.9 will take the blue fluid, while all cars with a model year of 2010 or earlier will be red. 2011 model-year vehicles may serve as fringe cases and will need to be checked by their producing date or VIN (more on that in a second) to determine which they fall into.
VIN Decoding
As a surefire way to ascertain which fluid your transmission takes or even just as a confirmation of your hypothesis, a VIN decoder will definitively point to the fluid needed. Simply paste your vehicle’s VIN into the decoder and allow it to pull the pertinent information. Once this screen has loaded, we have two places to check for confirmation of fluid type.
Using a generic salvage auction vin for a 2012 E550 with a 722.9 and scrolling to the bottom of the page, we see the options package on the specific vehicle at hand. After having the VIN decoded, the vehicle being considered shows the above options code, and as the A89 option package is directly indicated, this vehicle will receive the blue fluid.
As a method of fact-checking or confirmation, you can scroll back to the top of the same VIN Decoder page and locate the transmission model number and serial.
The engine model and serial are highlighted in the first red-text line (this vehicle is equipped with an M278.922 engine), and the transmission info is presented in the second red-text line. In this case, the transmission model is a 722.909. For the sake of locating the transmission’s serial number on a 722.9, the zero is dropped. The serial number of the 722.9 in this vehicle would be 3629862.
Compare that against the official Mercedes documentation on 722.9 fluid types below.
The serial of the 722.9 at hand is well after the A89 changeover serial of “2834527,” and therefore, we’ve reaffirmed that this vehicle would require late-model fluid.
Mercedes 722.9 Transmission Internal Determining Features
Sometimes, the most trustworthy source for an issue like this can be putting your own eyes and hands on the unit in question. These are a bit more subjective if you’re a second/third/fourth owner of a 722.9 car, as there’s always the possibility that parts have been upgraded or the wrong fluid has been installed, but will generally point you in the right direction.
Check the Pan/Pan Upgrades
The 722.9 and 722.9 “Plus” transmissions used two different styles of transmission pans primarily as a byproduct of using different filters, which means we can use differences in the pans to indicate which fluid should be inside. On the pan on the right in the image below (courtesy of Mercedes), we see that 722.9 “Plus” models have deeper dimples and additional clips on the pan itself.
You’ll also notice that the rightmost pan appears deeper than the early 722.9 pan, and it is. It’s to accommodate the trademark “SmartMedia” Triple filter used by the 722.9 Plus” models, which are physically larger than the standard filter. As this filter is the latest in filtering technology for the 722.9, as well as the fact that the deeper pan allows for a greater fluid capacity and more certain lubrication, we offer a retrofit kit that contains everything required to swap the SmartMedia filter and deeper pan onto a traditional red-fluid 722.9 (of course, while these components are upgraded, the early transmissions would still require the red fluid). The deeper pan, SmartMedia Filter, and the additional contents of the kit must all be installed together to complete the retrofit.
Check the Overflow Plug
The retrofit kit also includes the required overflow plug that is designed for the SmartMedia filter, which differs in color from 722.9 to 722.9 “Plus” models and is another way to tell the transmissions apart. A green overflow pipe is a hallmark of the 722.9 “Plus” SmartMedia filter and deeper pan, while traditional earlier 722.9 models will use the white overflow pipe.
One should be cautious when using these methods to gather which fluid is needed for their 722.9, though. Of course, if the car is bought secondhand, a previous owner may have completed a retrofit or upgrade similar to the one mentioned above; similarly, while many DIYers base the fluid needed for their transmission upon whichever color comes out of the unit when they remove the drain plug, the unit could very possibly have been filled incorrectly by whoever touched the unit last. In either instance, using the practices above could lead you to purchase and potentially install the incorrect fluid.
Locate the Serial Number
The safest physical method to determine the fluid required by your 722.9 is to find the transmission-specific code stamped into the unit itself and compare it against the inflection point Mercedes used between red and blue fluid models. This will again require the information presented underneath the VIN Decoder section above, but rather than decoding the unit online, we would simply compare the Mercedes-specified serials to the transmission’s serial.
The leftmost picture indicates the transmission’s serial stamping, which will face downwards and will be between the bell housing and transmission pan on all 722.9 models. On the stamp seen in the right photo, we have three distinct lines noted:
- Line 1 is the part number of the overall assembly, as the transmission corresponds to the model and engine at hand (not entirely relevant to us in this service).
- Line 2 is the model of the transmission and its variant. The model in the photo would be a 722.9 transmission and, by variant, a 722.902. This information may be good to know for a service but isn’t all that helpful in determining which fluid is needed.
- Line 3 notes the serial number of this transmission. In the case of this photo, we see “1822427.”
As blue-fluid 722.9 “Plus” models extend from serial “2834527” and beyond, and the vehicle at hand is “1822427,” our example vehicle can conclusively receive red fluid for its service.
The lack of a cut-and-dry year split for the 722.9 models can create a good deal of difficulty when you’re simply trying to complete a transmission service on your own. Fortunately, combining any two or three practices from above can point you in the right direction with certainty (alternatively, using all of the above can provide an open-and-shut case).
722.9 “Red” Service Intervals and Info
Mercedes BeVo Requirement: 236.14
Service Interval: Every ~40,000 miles
722.9 Plus “Blue” Service Intervals and Info
Mercedes BeVo Requirement: 236.15
Service Interval: Every ~70,000 miles
Now that you know which fluid is required for your next transmission service, feel free to head to our 722.9 Owner’s Guide to learn a bit more about your 7G-Tronic Transmission.
Mercedes 722.9 Transmission Frequently-Asked Questions
What should I do if the incorrect fluid color is being used in my 722.9?
These gearboxes are built to specific tolerances for maximum performance and reliability. Because of the difference in viscosity between the red and fluids, using the wrong fluid will cause some kind of damage. We recommend performing a drain and flush immediately if the incorrect fluid was used.
Can I upgrade my 722.9 to function like a 722.9 “Plus” so it takes the blue fluid?
Not easily. You can, however, retrofit some parts from the Plus transmissions to improve the reliability and longevity of your red-fluid transmission. You can find a kit for that here.
I’m having drive issues with my 722.9. Where should I start?
Just as you would with an engine-related fault code, step one for transmission diagnosis will always be to scan for any fault codes with an OBDII scanner. We have a bunch of those fault codes mentioned in our 722.9 Guide, which may help you to diagnose the issue. Regardless of fault code, though, a wise choice is always to check that your 722.9 has the appropriate amount of fluid and that the fluid is clean. It should also be noted that for AMG models, a replacement of the conductor plate isn’t always possible; 722.907 models use a torque converter and can have a conductor plate, but the other AMG vehicles will use a wet-clutch system and will need a full valve body replacement.