meazz1

It's time for a transmission service on my C250, It at 75k miles.
Has anyone done this or had a shop do it for you?
If anyone did do it please share your DIY experience and tips.
I already have an bluetooth OBDII device to measure tranny temp, a ramp and other tools. Only thing I will need is a fluid pump.

soldr230

Fill adapter (silver plastic; Fleabay)
Laser Temp (Garber Freight)
transmission filter
6 liters of transmission fluid (without convertor drain)
10 liters of transmission fluid (with convertor drain)
1 set transmission pan bolts
1 gallon garden sprayer (LLowes)
1 drain plug and washer
27mm socket for harmonic balancer
laser thermometer

Seeing that you have a C250, you will more than likely need blue transmission fluid and a fill adapter. You should probably source the fill adapter ahead of time because I doubt that you can find it locally. You do not need a fancy pump with a shut off valve. A cheap ($10 dollar) garden sprayer from LLowes has the same capabilites as a fancy pump with a shut off valve.




If your car has a torque convertor drain plug, you will need about 10 liters of fluid. It is likely that you do not have a drain plug on your convertor. If you do not have a drain plug, you will need about 6 liters of fluid. If your C250 is equipped with a torque convertor drain plug, you will need a drain plug washer and a 27mm socket. You will also need a new transmission gasket and filter. Please do not forget the transmission pan bolts. As you know, the procedure cannot be accomplished without a fluid pump and a devise to measure transmission temp. You will discover the transmission mount is easily accessible. It is also important to note that the (green) plastic tube in the transmission pan is reusable.

Raise and level the vehicle. The feat can be accomplished with a hydraulic jack and four stands. After the vehicle is raised and level, place the transmission in neutral and turn the harmonic balancer clockwise with the 27mm to access the drain plug. If you have a drain plug on the torque convertor, drain the fluid. If not, move on and drain the transmission pan. Remove the drain bolt on the transmission pan and capture the fluid. After the fluid has drained, insert a thin allen key and dislodge the (green) plastic tube. The plastic tube is inside the transmission pan and will release additional liters of fluid when disturbed.

Remove the transmission pan and replace the (green) tube and filter. Clean the transmission pan and magnets. Finally, measure the old fluid and install the pan gasket. If you do not have a torque wrench, you can tighten the new bolts hand tight and the pan will not leak.

Connect the garden sprayer hose to the fill adapter and pour a gallon or 4 liters of transmission fluid into the garden sprayer. Pump 4 liters into the transmission. After the initial 4 liters is depleted from the garden sprayer, add 2 additional liters and pump the sprayer. The transmission should have 6 liters of new fluid and you can start the vehicle. (Do not remove the hose or the fill tube. Keep the garden sprayer attached to the transmission.)

Start the vehicle and place your foot on brake pedal. Take your time and shift through the gears. Shift back to park and climb under the W204 with the engine running. Allow the vehicle to reach 45C. It may take 15 minutes or more to reach 45C. To acquire a close reading, use an ODBII scanner. If you do not have a scanner, you can point a Garber Freight laser at the pan bolts, the pan, and the torque convertor. At 45C (quickly) pull the rubber hose off the fill adapter. After you pull the hose off the adapter, a healthy stream of fluid will pour out. As soon as the fluid starts to dribble, unscrew the fill adapter and install the drain plug.

Don't forget to recycle the old transmission oil!


10 buck sprayer

meazz1

@soldr230
WOW!!
This is the most detail DIY I ever came across. I really appreciate this.
How do I know if the car has a torque converter bolt?.

soldr230

You may or may not have a torque convertor drain bolt. It will be fairly obvious.

Safely raise and level vehicle
Remove plastic shield(s)
Remove small rubber access cover to gain access (6 o'clock) or (9 o'clock)
Shift into neutral
Place 27mm (shallow) socket on the harmonic balancer and turn clockwise
Slide under the car
Look for drain plug on the torque convertor
If you do not see the drain plug
Turn the 27mm socket clockwise
Look for the drain plug
Repeat until you find the drain plug or give up

ronbutchart

Just to be clear; if you don't have a torque converter drain plug you won't be able to drain it and will thus need to refill the pan with 6 liters of new fluid. If you DO have a drain plug and choose to remove it to drain the TC along with the pan do you just use the fluid pump (garden sprayer) as previously described but add 10 liters of fluid followed by the warming up, walking through the gears and then removing the fill adapter to let the fluid find the right level?

soldr230

1. If you are just dropping the pan and changing the filter, add 6 liters.

2. If you are draining the convertor and the transmission pan, add 10 liters, BUT only add 7 liters or so Before the warm up. After you start the car wait a few seconds and add the final 3 liters.

After the transmission has 10 liters of fluid, shift through the gears and wait until 45C and pull the hose from the adapter. After you pull the hose off the adapter, a nice solid stream of fluid will pour out. As soon as the stream starts to dribble, unscrew the adapter and install the drain plug. It is really super simple and almost fool proof as long as you have enough fluid and a means to measure temperature.

I purchased 10 liters before I realized that I did not have a drain plug. I managed to find a way to incorporate the 10 liters, but it was very time consuming and would take a few paragraphs to explain. Let me know if you are interested in that process.