As one of the most well-known car brands in the world, Mercedes had its start in 1925. It was created through a merger of Daimler-Motoren-Gesellschaft (DMG) and Benz & Cie. encompassed by Karl Benz, Gottlieb Daimler, Wilhelm Maybach and Emil Jellinek. Their daughter was named Mercedes, and they would originally name the brand after. In 1926, they became Daimler-Benz AG.

In 1936 Mercedes-Benz released the W136 model and the first diesel passenger car. Later the W135 roadster and W138 limousine were introduced until World War 2 stopped production. In 1963 the first automatic transmission was introduced, and in the 1990s Mercedes-Benz became one of the first car brands in the early ’90s to remove harmful CFC chemicals from their air conditioning systems.

Now, there are offices in 93 locations worldwide and a corporate headquarters in Stuttgart, Germany. These cars are manufactured in 17 countries on five continents and distributed all over the world.

What Does a Transmission Do?

In a car, the transmission transfers power to the wheels in order to push the car to the speed at which you which to travel. The gears are shifted in the same way as a bicycle. Poor transmission leads to a host of problems. This is why you must keep your transmission well-maintained, avoid losing both fuel economy, and prevent costly repairs.

There are two types of basic transmission types, automatic and manual. Modern times see more automatic transmissions placed into cars than manual transmissions because it is more difficult to drive a manual transmission. It takes a lot more of a learning curve and is impossible to drive if you have not to be taught properly.

In a manual transmission, pushing the clutch disconnects the engine and transmission. When you press the clutch pedal you are able to adjust the gear shift and move into a different gear. Once you move into the correct gear, you release the clutch to continue on to drive.

The transmission usually has a cylinder that spins and provides power to turn the wheels. The “Engine speed” is how fast the crankshaft spins, and it is measured in RMPs, (revolutions per minute). Most engines make their power within a small number of speeds, by actually driving requires more of a range. The transmission is essential to increase torque before stopping or preventing the engine from overheating.

The Automatic Transmission

An automatic transmission is quite simple to drive, you simply put the car in drive and then go. Despite this, it may appear effortless, but there is a lot going on. Automatic transmissions are just as complex as manual transmissions.

An automatic transmission uses sensors in order to determine when it should shift gears. It will change them using internal oil pressure. When there are multiple types of components placed in the transmission, it can get complicated, which is why it can be extremely expensive to work on the transmission.

Signs/Symptoms of a Bad Mercedes Transmission

If there are any strange noises, smells, sights, or movements in your car then it might be the transmission having troubles. Common signs of a bad Mercedes transmission include:

• Having higher than normal RPMs
• Accelerating slowly
• Not able to reverse
• Burnt smell
• Difficulty shifting gears
• Check engine light

Warning Lights

In modern cars, there are check engine lights which are wonderful because it allows you to know when things are going wrong. In Mercedes, these censors are pretty intelligent and can notify you before things get worse. If the check engine light comes on you will want to bring your car into a shop as soon as possible.

Leaking Transmission Fluid

Any kind of leaking is always a bad situation, and one of the most common causes of transmission problems is leaking transmission fluid. The transmission fluid is essential if you want your car running smoothly, and any type of leak can cause a problem.

Transmission fluid is very obvious, it has a bright red color and leaves a sweet smell on your driveway or parking area. Whenever you see this, it is a bad sign. Reasons for leaking transmission fluid include:

• Wearing out of gaskets or seals
• Bad connection of the cooler lines
• Any type of pan leak
• Lack of balance in the area of the drive shaft
• Dysfunctional bell housings
• Worn out mounts, engine or axles

Checking transmission fluid levels is a simple task, but also incredibly essential. You can do this yourself if you have a bit of training using only a dipstick.

To understand whether or not you need to replace the transmission fluid, you should pull out the dipstick while the car is running. You can then rub the fluid between your fingers and if it has a clear or pink color you should be fine.

If the fluid is burnt-smelling or is a completely different color, you might have an issue. Especially if the fluid is clear but doesn’t reach the “Full” line on the dipstick, then you need to replace some of it. Do not overfill it, but check with your owner’s manual to see which type of transmission fluid your car needs.

Weird Noises

Any type of weird noise should be a cause for concern. Your transmission should not be noisy. If you hear any type of grinding then you have a problem. When you press on the clutch in a manual it should be smooth and quiet, if this is not the case then you have trouble. Your clutch may be out if it is too noisy, and you may also notice that you struggle to switch gears.

An automatic car is supposed to have a smooth transmission, especially in a Mercedes. In this case, you may notice gearshifting or humming noises, which are not normal, then it may mean you need to have them checked.

Odd Smell

In order to indicate when it is in a good place, your transmission fluid will smell very sweet. If it smells like burning, this is a major problem because it means your Mercede’s transmission is not in good condition. This means you may need to replace your transmission fluid to avoid damage to your vehicle.

Skipping

If you notice any type of delay then it may be an issue. In the past vehicles were not as smooth, but Mercedes is now known to be both smooth and effortless. If there is any change in how your vehicle operates, especially if you are using a manual, check your clutch. There may be delays while in the park or drive if you have an automatic car.

What Mercedes Models Have Transmission Issues?

Mercedes-Benz C 300

In a Mercedes-Benz C 300 transmission, there are various Mercedes-Benz C 300 transmission problems. For transmission, there are a series of parts that might be too much for your to troubleshoot. In this case, you will need to replace the sensors rather than repair them. You may also need to lift up the car in order to reach these places. This is why you need to go to a transmission expert. Another problem in these vehicles is a broken oil pressure switch. This should be replaced and tested properly before moving on to driving normally.

When it comes to an automatic transmission fluid replacement, you may need to replace your pan gasket and filter. This requires the fluid to be drained and to ensure there are no leaks. In the Mercedes-Benz C 300 transmission, you will need to replace the fluid every 30,000 to 40,000 miles.

Generally, Mercedes-Benz C 300 transmission problems can be easily handled by listening, looking, and ensuring that there are smooth conditions while driving. Always test for smoothness while in a frequent stop-and-go setting.

Common Transmission Problem: Stuck in Gear

If your transmission is stuck in gear and you are far away from home, there is a way to try and rectify this,

1. Pullover and turn the car off.
2. Remove the key.
3. Avoid pressing the gas or other buttons.
4. Wait 30 seconds.
5. Start the car and drive.

If your transmission is back to normal, there may still be underlying issues. Do not ignore them because this is called “limp mode.” If you ignore this warning then it may not shift, or go back into limp mode.

Most transmission problems are hard shifting or no shifting issues. These usually come from incorrect fluid levels or an issue with the transmission 13 pin connector plug O-ring. This is easy to fix and typically you will not even need a complete transmission replacement. The 5-speed transmission that was used between 1995 up to 2008 is one of the best Mercedes transmissions, after that year there are more issues.

Easy Mercedes Transmission Fixes

Replace 13 Pin Connector Adapter Plug O-ring

If you scan the car through a mechanic and find communication issues with the valve body or issues with the gear ratios this can be extremely expensive. To avoid this, you can instead replace the Mercedes Transmission 13-Pin Connector Adapter Plug + O-rings.

The O-ring plug leaks oil and can cause issues between the TCU and valve body. If you are working with a mechanic not familiar with Mercedes-Benz transmission, then they may suggest replacing the whole transmissions. This is a very bad idea and completely unnecessary.

Replace Valve Body

If you are continuing to have an issue going into limp mode and the scanner pointed you in the direction of the valve body, then you most likely should replace this. At a dealer, this may cost anywhere from $500 to $1000, but more if you do not go to someone who knows what they are doing because it will take longer. Replacing the valve body can perform with the transmission in place. This is great because valve failures are common.

You can find valve bodies on Amazon and bring this to your mechanic if you wish. The only consideration is that when it comes to a 722.9 you will not be able to use it due to the control unit being part of the body. In this case, you will need to get a new body or find a Mercedes-Benz 7G 722.9 conductor plate repair service. These are independent shops that will take your old 722.9 transmission control module and attempt to make repairs to it.

Failed Transmission

Very few Mercedes-Benz cars completely fail. In this case, you will require transmission replacement. Your transmission will fail in rare cases if any water enters the transmission via the oil cooling lines. In this case, the radiator on these cars equipped with Valeo radiators, and the top part holds the coolant/antifreeze.

The bottom part however has a chamber that offers a place for the transmission oil to cool. If cracks develop between the two chambers, then coolant will mix with transmission oil. This is a huge problem as it will destroy the transmission. This has been a well-documented issue for Mercedes-Benz cars that have the Valeo radiators. If your transmission fails then you may want to consider a remanufactured or even a used transmission with low miles. This will be the difference of 1000’s dollars.

Is Fixing Your Mercedes with Transmission Problems Possible?

Repairing your Mercedes transmission is a very expensive situation, but it is an essential part of your car. Despite this, it can not only be a difficult job for a mechanic to perform, therefore it may be impossible for you. It is not recommended that you do this yourself because of all the different working parts involved.