Hello everyone, this is a column focusing on car repair and maintenance. There are car secrets you don’t know here, and it will teach you how to avoid big pits on the road to car maintenance. I believe that not only you, but also many people have a certain hazy feeling about the automotive aftermarket. Here will help you uncover the unknown stories of car repair and maintenance.
This is a Mercedes C200 model equipped with a 2.0T turbocharged engine.
This C200 is equipped with Mercedes-Benz’s own 7-speed automatic manual transmission and comes with shift paddles. Since the number of kilometers has reached 80,000 kilometers, it is time to replace the transmission oil.
First, the engine guard plate is disassembled. This is a guard plate made of hard plastic material. The main purpose is to integrate the airflow under the vehicle and improve the stability of the vehicle at high speeds.
After removing the guard plate, drain the oil through the oil pan drain bolts. This is only the first step in draining the oil.
The oil overflow hole for the removed oil pan is the oil drain bolt on the oil bottom just now. The same hole is used as the oil spill hole, and the green pipe above the oil drain hole is the stop surface when filling the transmission oil. Once the oil is filled to this plane, the oil spill hole will begin to leak. At this moment, it means that there is enough transmission oil and no need to be filled.
This is a permanent magnet that is adsorbed on the oil pan. The main purpose is to absorb mechanical residue generated by wear of the gearbox. These metal debris powder have a huge impact on the performance of the gearbox, so it is necessary to replace the gearbox oil in time.
The filter element for gearbox oil is really a completely different design from the ZF gearbox.
The removed oil base pad has undergone serious keratinization. Frankly speaking, rubber products will become hard and brittle after a long period of high temperature. Its own fit and elasticity have been basically lost, and of course, its tightness has been lost.
The oil pan is much cleaner after cleaning.
For the new oil base pad, the inside of the flat rubber pad can be seen in the enlarged window on the right.
A new filter element has also arrived. The interior is a kind of filter cotton. You can see in the window on the right that the filter cotton is wrapped in iron sheet and integrated together.
During the installation process of the oil mat, remember to install it in place and spread it flat. Otherwise, squeezing will occur, which will lead to loose sealing and leakage of transmission oil.
Install the subsequent transmission oil filter.
A lot of gearbox oil.
Due to the gravity oil change method, a manual oil dispenser is used to fill the gearbox oil. In fact, it is a manual oil pump that applies pressure to the gearbox oil and injects it into the gearbox.
The refueling hole is both an oil drain hole and an oil fill hole. Waiting for oil to flow out of the oil spill hole means that enough oil has been added to the gearbox. After installation of the transmission oil pan, the Mercedes-Benz oil pan bolts are tightened through a small locking block, which places very high requirements on both the installation method and the tightening torque of the bolts.
After the oil change is completed, the test run is carried out. The gearbox shifts actively, accelerates smoothly, and there is no feeling of frustration.
SallyBessemer 
1 
September 18, 2024 
