I’ve now owned my Mercedes-Benz E-Class W211 320CDI with the 7G Automatic Transmission for 4 years. During my time of owning this car and transmission, I have to admit, I did not experience any major problems.
I did, however, made a full analysis of every potential problem that is known to happen with this transmission before I decided to purchase a Mercedes with the 7G Mercedes.
I will first reveal the specs of the 7G Tronic transmission, and then I’ll continue with all the Mercedes 7G transmission problems. If you’re not sure which transmission is in your Mercedes, I’ll also name all the models that were fitted with the 7G transmission.
Basic Mercedes 7G Automatic Transmission Specs
The 7G-Tronic transmission is an automatic transmission developed by Mercedes Benz in the early 2000s. This transmission was in production between 2003 and 2020. It was recently replaced by the 9G-Tronic transmission we talked about recently.
What is interesting to note about the 7G-Tronic transmission is that this transmission is a longitudinal design. Meaning that it serves the purpose only in rear-wheel-drive vehicles. It can handle massive amounts of torque. Specifically about 700 N-m or 520 lb-ft of torque.
The overall design is a classic torque converter automatic and this transmission has 7 forward gears and two reverse gears. More gears mean smoother power delivery and overall smoother drive experience.
On top of that, this 7G-Tronic is also very efficient because it implements a lot of forward gears. So, if you cruise on the highway, you can do this without pressing on the throttle quite a lot. Which will save you a ton of money on gas compared to the older 5G-Tronic.
Common Mercedes 7G Automatic Transmission Problems
Common problems with the 7G automatic transmission include:
- Doesn’t Work Well In Cold
- Delayed Or Unpredicted Shifting
- Hard Shifting
- Slipping Gears
- Defective Conductor Plate
- Stuck In 2nd Gear (Limp Mode)
- Water Can Damage The Transmission Housing
- Transmission Failure
Doesn’t Work Well In Cold
The 7G-Tronic transmission can be said that it doesn’t like to work well in cold temperatures. Whenever you start the engine in freezing temperatures, the transmission might feel strange. I definitely notice that with my W211 and its 7G transmission.
This is a problem, if you can call it that, which only persists until the transmission warms up. Once it warms up, the problem disappears and you will not experience it again. This is a common occurrence with all modern automatic transmission, give them the time to warm up and don’t push it or do kick downs during the first 10–15 minutes.
Delayed Or Unpredicted Shifting
One of the most common issues with the 7G-Tronic transmission is delayed or unpredictable shifting.
These problems are reportedly caused by bad software on the transmission (an issue most cars have resolved by now) and by malfunctioning solenoids on the valve body (which mostly happens on poorly maintained examples and those with extremely high mileage).
The recommended procedure is to update the software first and then if the problem persists, to move on replacing faulty components. In any case, an experienced transmission technician will be able to diagnose both issues without simply blindly replacing expensive components.
Hard shifting is another common problem on these 7G-Tronic transmissions. When healthy, the 7G transmission should deliver silky smooth gear changes with very little to no bumps (maybe a little one when doing a full blast off from a stand point). All other repeated signs of hard shifting need to be closely examined.
Common reasons behind this problem can simply be cold weather, low transmission fluid, dirty transmission fluid, worn-out solenoids, worn-out transmission internals or problems with the Transmission Control Unit, or possibly problems with the software of the TCU.
The important thing is that you solve this problem quickly because it could be a sign of a serious issue. Remember; you never wait it out with transmissions, it’s never going to get better, only worse and more expensive to fix.
The next problem with the Mercedes 7G-Tronic transmission is the case when the transmission is slipping gears. So, what does this mean?
Well, this means that the car is not shifting very smoothly from one gear to the other or the car simply drops a gear without any notice.
This problem reportedly happens between 1st and 2nd gear on this transmission. And whenever this problem gets detected, the transmission will go into limp mode.
Limp mode means that the transmission is in safe mode. It can’t be pushed harder because you can and will damage it.
The reason behind slipping gears can either be a faulty torque converter or an electronic/software issue. Either way, professional diagnostics are a must.
Defective Conductor Plate
This transmission has one huge problem and that is the defective conductor plate. So, what is a conductor plate?
This is a special plate that is used in automatic transmissions. This plate is attached to the valve body of the transmission. On this plate, you have the pressure release valves, speed sensors, as well as shift control valves.
In general, this plate transmits the signal to the valves. This signal is understandably sent by the TCM.
This is not a common thing to fail on other transmissions. But on the 7G automatic it is a very common thing.
The problem starts intermittently at first, but then it becomes a permanent issue that has to be resolved in order for you to keep driving your vehicle as it should.
The problem makes the transmission stay in one gear and then shift to the next gear rather erratically. This causes that rough or hard shifting that we mentioned previously.
Unfortunately, this is a very expensive problem to fix. It can cost up to $550 only for the part and it is a major headache to a lot of Mercedes-Benz owners.
Also, it is recommended that you go for a newer and updated conductor plate. Go for version 2 (VGS2 )or possibly version 3 (VGS3). Version 1 (VGS1) is the one that fails most often.
On Version 1 you have to replace both the valve body and conductor plate. While on Version 2 or Version 3 you only have to replace only the conductor plate when you have this issue.
In addition to this, you also have to code the new conductor plate to work with the transmission.
Stuck In 2nd Gear (Limp Mode)
Another fairly common concern with the 7G-Tronic transmission is the case when the transmission ends up stuck in 2nd gear.
Many owners reported how their transmission ended up stuck in 2nd gear once they accelerated from a stop light.
This issue is reportedly caused by the transmission seeing some problems and the TCM decided to go into limp mode.
The solution to this problem is to take your transmission to the nearest service center and have the transmission checked. It can be something simple, or it can be something very serious, I’ve heard about 20 different stories about the things that were at fault for this symptom.
Water Can Damage The Transmission Housing
Reports in which owners reported rust development on the transmission housing are also quite common.
Upon further research, I found that this problem was reportedly caused only in cases of serious flooding and the car sitting in water for prolonged periods of time.
This is not something scary since this is an issue that rarely happens, only in cases with serious floods.
The last problem on our list is the case when the transmission completely failed. And this can happen on the 7G.
Usually, when it happens on cars with very high mileage, or in case the transmission was not serviced regularly. Regular transmission fluid changes on any automatic transmission are absolutely crucial!
In order to be sure that the transmission is good, make sure that you do a test drive first and see how the car is shifting. If you notice any lights or rough shifting, you should take it into consideration and possibly lower the price to cover the repairs.
In any case, the previous owner should provide you with at least some proof that the transmission oil has been regularly replaced. If there’s absolutely no proof and you get a feeling that the gear changes aren’t as smooth as they should be, I recommend you pack your things and run, seriously.
Which Models Have The Mercedes 7G Automatic Transmission?
- 2006 – 2014 Mercedes Benz C-Class
- 2009 – 2016 Mercedes Benz E-Class
- 2013 – 2020 Mercedes Benz S-Class
- 2011 – 2015 Mercedes Benz SLK-Class
- 2005 – 2010 Mercedes Benz CLK-Class
- 2014 – 2019 Infiniti Q50
- 2017 – 2018 Infiniti Q60
- 2017 – 2020 SsangYong Rexton G4
What Are The Common Mercedes 7G Transmission Problems?
Common problems with this transmission can include limp mode, hard shifting, slipping gears, defective conductor plate, and transmission not working properly when cold. The biggest issue with this unit is the conductor plate issue. This component can fail and cause a ton of problems with shifting. Also, it is very expensive to fix.
Is The Mercedes 7G Automatic Transmission Reliable?
The Mercedes 7G transmission is reliable, but it has a weak point. That is the conductor plate failure. This component can fail and can result in very expensive repairs. So, make sure that you are aware of this before you decide to buy a car with this transmission.