The Mercedes Benz 9G-Tronic 9-speed transmission is one of the very first 9-speed transmissions found in the premium luxury segment. The 9G-Tronic was first showcased in the 2013 Mercedes E350 Blue Efficiency and was later incorporated in all succeeding Mercedes models, starting from the W222 S-Class.
As mentioned, the 9G comes with 9 gears in order to maximize efficiency and minimize power loss while the clutch engagements and shifting times have been reduced from the previous 7G-Tronic gearbox. All in all, the 9G-Tronic is an all-around upgrade over the 7G-Tronic and is still present in many Mercedes models.
The 9G-Tronic comes in both torque converter and multi-clutch form that is basically a 9G-Tronic, but without the torque converter. Even though the majority of people who drive Mercedes models with this gearbox have many positive things to say, the 9G-Tronic is not without its share of issues.
Most common 9G-Tronic issues include rough shifting, slow shifting, grinding noises, lackluster acceleration, and problems with the solenoid. This transmission needs constant maintenance if you want it last, but other than that, it is a relatively dependable box.
Mercedes 9G-Tronic rough shifting problems
Many owners complained about their 9G-Tronic Mercedes models experiencing rough shifting, especially while shifting from neutral to first, or from first to second. This tends to happen both while the cold and while the car is warm which makes the issue even more worrying. Some owners said that performing a restart solved this issue, others say that it does not.
Some people go as far as saying that you should not be surprised if you experience jerky shifts with the 9G-Tronic, but the reality is that issues such as these do influence the overall durability of the transmission. The best thing you can do is contact a Mercedes dealership and take your car for a complete diagnosis.
Mercedes 9G-Tronic slow shifting problems
The Mercedes 9G-Tronic is a state-of-the-art transmission that is available in many performance-oriented Mercedes models. It is not a dual-clutch box which means that it does not go through gears as fast as something like a Porsche PDK, but no one can say that the 9G-Tronic is slow.
Either way, if you experience your 9G-Tronic being lazy while going through the gears, you should first wait until it reaches optimal working temperature. If the issues persist, you should take your car to the dealership as slow shifting tends to be a symptom of worn-out mechanical components or an issue with the software.
Mercedes 9G-Tronic grinding noises
In order for the 9G-Tronic to fulfill its duty as intended, it needs constant fluid replacements, more specifically you need to replace the fluid every 4-5 years depending on how many miles you do yearly. Either way, grinding noises tend to happen due to metal fillings and particles in the transmission fluid.
These issues also often lead to a faulty electro-hydraulic converter so be sure to have yours inspected if your 9G-Tronic suffers from similar issues. Many owners have reported vibrations and grinding while driving at highway speeds in higher gears. It is not yet clear if that has something to do with the transmission specifically.
Mercedes 9G-Tronic slow acceleration
The previous generation 7G-Tronic is known for rapid acceleration times, and when the 9G-TRonci was introduced, the acceleration times improved even further. If you buy a higher-end AMG model, you are also getting the launch control function which makes sure you are always getting the most rapid acceleration times possible.
However, many owners have reported two issues associated with acceleration. The first one is that the car is unwilling to engage launch control or unwilling to stay in launch control mode. Sometimes the gearbox is unable to properly decide which gear is necessary for optimal acceleration times which means that your car accelerates slower than usual.
Mercedes 9G-Tronic solenoid issues
The 9G-Tronic gearbox is designed to engage limp mode whenever something causes a more critical error to preserve the gearbox from further issues. If the solenoid fails, the car transmission will completely disable the gear affected.
This means that the gear in question will not be actuated and the car will likely go into limp mode. If this happens, you have to take your Mercedes into a dealership. Do not attempt to reset the gearbox yourself as limp mode is designed to engage only when the transmission is experiencing issues that can cause a lot more damage.
Is the Mercedes 9G-Tronic a good transmission?
The Mercedes 9G-Tronic is indeed a really good transmission because it offers great power delivery, is able to endure lots of torque, and because it is smooth and cohesive. The 9G-Tronic also maximizes efficiency by constantly shifting gears according to the driving mode you are in.
The transmission is superiorly responsive which means when you engage kick down in sport mode, the car will always find the right gear to be in which means that the 9G-Tronic is good at everything. Higher-end V12 Mercedes models typically avoid using the 9G-Tronic because the 7G-Tronic is a better choice for higher torque engines.
How to reset the Mercedes 9G-Tronic gearbox?
If you want to reset your 9G-Tronic transmission after an oil change or for any other reason, be sure to follow these steps. However, do not attempt to do this if you are not 100% aware of what you are doing. Always consult with your dealer when it comes to performing dealership tasks yourself.
Put the key in the second position and don’t start the car. Hold the accelerator pedal in the kick-down position for 5 seconds without pause. Now it’s time to turn the key to the OFF position but without taking it out from the. After this, remove your foot from the gas pedal and wait 2 minutes before the system restarts itself.
Which are the best automatic transmissions in the world?
There are many amazing automatic transmissions around the world but it seems like the Porsche PDK dual-clutch might be the best one of them all. The reason being is the PDK offers incredibly smooth and fast shifts, so much so that the smoothness the PDK offers is keener to a torque converter than it is to a DCT box.
Secondly, the PDK is able to endure constant launch control. The DSG(S-Tronic) gearbox found in other VAG products is also amazing, but it is not as smooth as the PDK. The Steptronic automatic gearbox in some BMWs is also one of the best gearboxes on the market.