rickiteasy

For those DIY owners, I just changed the transmission oil and filter on the 2017 GLC300 with 40,000 mile. I thought I would share it here.
Mercedes recommends changing it at 60,000. I think 40,000 mile is good enough for me to change. Read and study it before you start draining out the old oils
because there is no filling hole on these new Mercedes, if you have not noticed. On one hand, it is not an easy job like changing your engine oil.
But if I have some skills and the right tools, it is not rocket science.
Supplies:
* 10 liters of transmission oil (trans oil for short) for the 9G-tronic transmission. I used the febi brand. You can use the Ravenol or other brand.
* Transmission filter & pan. They do not sell the filter alone. You have to replace the filter and the pan. The filter is glued to the pan. Interesting design.

Special Tools for this job (not going to list the normal tools like screwdrivers...etc. haha) :
* Transmission Oil Filling Tool - 9-speed oil change Tool. Benz 9G-Tronic Transmission Oil Adapter Set.
* ATF109 transmission filler adapter fitting (This screws on to the filling adapter set above)
* Performance Tool W54170 12V Oil Extraction Pump (or something similar). Or if you have another person to help, you could use gravity to get the oil in the transmission through the drain hole.

Tools in my situation, since I do not have a power lift. Your situation might be different.
* Four rhino ramps to drive my GLC up to give me space to work.
* One floor jack.
* One bottle jack.
* Performance tool W50045 inspection camera (or have another person to help)

Now let's get to work:
To drain the oil from the torque converter:
Remove the 1" dia small plastic cover under the torque converter. You will see the torque converter through this hole.
You need to have the tiny torque converter drain plug lined up with this hole, so you can unscrew this drain plug.
To line up this drain plug, make sure the car is level with wheel blocks to keep it from rolling because you need the car to be in N neutral.

With the driver door open, start the car and shift to N neutral and turn off the engine. Reason is because the GLC will shift to P park automatically if you open the door as a safety feature. Thank you Mercedes for preventing many tragic accidents with drivers leaving their cars while the car is still in Drive or Neutral.

Now with someone under the car looking at the torque converter, you hand crank the crankshaft slowly in either direction until the drain plug is directly at the hole. In my case, that someone is my inspection camera near the hole.
If you do not have either, just crank a little and get under the car to look. Repeat until you see the drain plug. You do not have to go to the gym today after this.
Keep a good record of all the oil you drain out. I just put the same amount plus a small extra amount of oil to compensate for some spillage.
When I removed the torque converter drain plug, very little came out. One guy from Youtube had the same experience.
You should get about 3-4 quarts out from the torque converter. If you are getting very little, then the next step is to mark the crankshaft, so you know where the drain plug is.
Now slow crank the crankshaft in one circle to see if that would drain the oil. If that still does not drain the oil, start the engine and immediately turn it off. The oil started gushing out.

To drain and replace the transmission oil pan:
Here are couple sites to get you familiar with the procedure:

You Tube

https://www.youcanic.com/mercedes-be...n-fluid-change

Here are some of the tips to add from my experience:
1. Check the bolts around the transmission oil pan to make sure your tools can access all the bolts.
For my 2017 GLC300 4Matric, the center bolt towards the back of the car was blocked by the transfer case support bracket.
If this is your case, you have to put a jack with a small wooden block under the transmission oil pan to support the transmission pan to put the pressure off of the support bracket for the rear drive shaft U-joint.
Then remove the support bracket (with 4 bolts on each side of the bracket and 6 nuts under the bracket that attached to the rubber mount). After removing the bracket, then remove the rubber mount (4 bolts).
Next use a small wooden block and a bottle jack to support the transfer case, so you can remove the jack under the transmission pan.
Now all the bolts around the transmission pan are cleared.

2. The transmission pan drain hole is connected to a round pipe on the other side of the drain hole.
If you look carefully at the bottom of the transmission pan, you will see markings with 1, 2, 3, and 4.
It is hard to see because the pan is black and the numbers are just engraved on there.

Position #1. means the bottom of the tube is CLOSED. This is the position you want when finished filling and checking the proper oil level.

Pos #2. is used if you have the software hooked up to the GLC to monitor the temperature of the oil. And this is a small drain to let out some oil if necessary.

Pos #3. is the level where the extra oil will flow out. After you pump in the correct amount plus 1/2 quart to 1 quart more while the engine is running, any extra oil will start flowing out. When the oil temperature in the pan reaches between 35 C - 45 C and the oil flowing out is very little, then you have reached the proper level. When it has reached the proper level, discount the pump, turn the tube to Position #1, and put the drain oil cap back on the pan. You are finished.

Pos #4. is the max opening to allow you to drain most of the oil in the transmission pan.

Otherwise, when you just drop the oil pan without first draining the oil, you will have oil flowing all over the floor.
Even with most of the oil drain with setting #4, you still have about 2 quarts in the pan.
So, I would first loosen all the bolts around the pan, then remove all the bolts in the middle leaving the corner bolts holding the pan.
Then put something under the pan to support the pan leaving about an one inch gap.
Now remove all rest of the corner bolts. Most likely the pan is still stuck to the bottom of the transmission.
So, carefully pry the pan loose and hopefully the support will keep the pan from spilling the oil all over the floor.

5. The new transmission oil pan should have two tubes: one is connected to the drain hole with four different positions that you can adjust using the tube adjuster.
one is connected to the other side of the pan. They call this one the Guide Tube.

6. After you have put the torque converter drain plug back in (10 NM torque), you are ready to put the new transmission pan back on.
Wet your finger with some transmission oil and put it around the two o-rings of the two oil filters inside the pan.
With the transmission pan lined up to all the outside holes, put all the bolts back on evenly.
The pan should be tightened and drawn towards the transmission. This will slowly force the two oil filters inside the pan to go slowly into the holes inside.
This is designed to be a tight fit into the holes.
The torque for these bolts is 4 NM plus 1/4 of a turn more. My torque wrench only goes down to 5 NM, which is fine for me. No problems so far.
If you don't have a torque wrench, just evenly hand tighten all the bolts without killing it. This pan is made of plastic.

7. Now comes the fun part of filling it. With tube set to position #3 Using the special tool, connect the oil adapter (this looks like the drain plug except it has a brass female screw hole for the filler adapter pipe) to the drain hole.
Then connect the filler adapter (this has a male screw on one side and a straight smooth pipe on the other side, which is for connecting to the tube where you would pump the new oil) to this oil adapter pipe. I had to put some plumbing tape around the filler adapter before connecting it to the oil adapter because I was getting a slow oil leak between the oil adapter and the filler adapter. Then connect the oil extraction pump with one end to the filler adapter pipe and the other end to the bucket of new oil.
With the engine off, pump in about 3 quarts of trans oil through the filler adapter pipe.
Now start the engine and continue to pump in the rest of the new oil. I took out about 8.5 quarts. Please notice that the febi trans oil comes in Liter.
So, I put in a total of 8 liters + about 100 ml.

8. If for some reason, you could not exactly measure or figure out how much old trans oil you took out.
Here is how to fill it without any computer and software:
If you drained a lot out of the torque converter, most likely you drained out about 7 quarts - 9 quarts
Using Tip #7 above (make sure the position is set to #3), pump in a total of 9 quarts.
With the engine still running, put a bucket or pan underneath the filler adapter pipe, remove the tube from the filler adapter pipe. Some oil will start coming out of this filler adapter pipe. Now go into the car with foot on the brake, shift the gear from P to N to R to D each with 2-3 seconds in between.
So, how do we know how much new oil to put in?
The design is that Position #3 of the tube inside the drain hole has a opening set to allow extra oil to flow back out of the drain hole when the oil reaches between
35 degree Celsius and 45 degree Celsius. I have an infrared thermometer that I used to point at the bottom of the pan. But if you don't have one, just put your hand on the pan and feel the warmth. 100 degree Celius is a boiling water temperature. So, 35-45 Celsius is not very hot.
When the temperature is between 35 - 45 Celsius, remove the oil adapter and the filler adapter, then use the special tool to turn the Position to Position #1.
Then put the drain hole cap (this came with the new oil pan) back on the drain hole.

9. Reverse what we did in Tip #1 above to put the transfer case rubber mount and bracket support back on.

Now go for a test drive! Enjoy the fruit of your labor!

abacnus

wow, that is awesome, will save this post for sure.

DanD.

Thank you so much.
Wish you could take some pics.

Teckno

Thank you, excellent report.

my invoice for Dealer work included here.

Here is data from my invoice re 5 years auto and transfer case service.




I hope this helps you.
Cheers

rickiteasy

Thank you for sharing your invoice. It is not clear what the total bill is for the transmission and transfer case oil change. If it's $1995.91, then the numbers do not add up.

Teckno

Invoice ran into 3 pages due to formatting used. Total cost was around $2600. original quote was for $3500, which I objected to. Some discounting and revision by Dealer as we have been loyal customers and take an active interest in work undertaken.

George in KG

I normally do all my own service work, but this job was more than I wanted to tackle. Trans fluid change was $830 at my local independent (before taxes). $276 of that cost was labor and the rest was parts. $325 for the oil alone.

Thanks to the OP for posting the service procedure.

sn202020

Good writing. that recall my job details.

I replaced the 9g transmission oil and pan. Also rear differential oil for my 2017 glc at about 100,000km as DIY.

Cost was.
Trans oil. LiqiMoly 9 liters about cdn$150
Trans oil pan. Rockauto cdn$100
rear diff oil. Redline 1 liter $30
Total less than $300

About 5 hours job after watchig many youtube videos.

I measured the oil amount drained, then filled almost the same amount.

seamus2154

Great post thank you!! we just did our 2018 GLC300. We did it at 62K. I sent the trans oil in for analysis. It was worn out with low viscosity and high break in iron still floating aroung in there. Shorter interval recommended. Your 40K change was a good move.

Willie G

It appears 40k miles is the MB recommended tranny service interval. I had to scour the internet for a service interval manual (couldn't find it in MB software) and finally found a reference that said X253 transmission service at 40k miles which surprised me as that is the lowest I've ever heard of for a tranny. I just went over 40k in my 2017 GLC 43 and one of the service items that tripped in the car's Assyst Plus service menu was "Service 20" which is transmission filter and oil so it lines up. I keep seeing conflicting info that the transfer case & differentials are 40k or 50k, but I'm gonna do them all now for peace of mind. Thanks OP for the detailed write up!

seamus2154

Nope. its 60K. The Internet, and a reference both turned out to be incorrect. Its not 40K either. Page 3 AMG models are 30K and our model is 60K.

Willie G

That's interesting, for the AMG three year/30K mile interval, it says that only applies to AMGs with 177 engines (the V8), where as the 276 AMG engine (V6, *mine*) and 274 non-AMG engine (four cyl) are listed together below in the six year/60k mile section. I guess they want it changed more frequently b/c of the extra power from the V8?

All this conflicting information (and that "service 20" popped at 60k kilometers for me), motivated me to do some basic maintenance terminology word searching in WIS (don't know why my dumb a$$ didn't do this before, but hindsight is 20/20) and I found the service sheets. I found that the recommended intervals are different for tranny + region combinations. WIS showed the following five lists (my applicable interval is listed in parenthesis for each, 725.048 4 Matic:

*USA (60k miles or 6 years)
*SA Code 809=2019, excluding 805-808=2015-2018 (60k kilometers {~37k miles} or 4 years)
*SA Code 805-808=2015-2018, excluding 809=2019 (same as above for tranny, 60k kilometers {~37k miles} or 4 years)
*Rest of world high dust (didn't check b/c I'm not high dust in Tokyo suburbs)
*Rest of world low dust (125k kilometers, no time interval)

***edit*** I added a 5th service sheet (the 3rd one) to the above. It applies to my vehicle, SA Code 807, and excludes SA Code 809. I missed it because it wasn't in the initial WIS list of service sheets, but I found it with some digging through MSS. It has the same tranny interval as the service sheet for SA Code 809 (that excludes SA Code 807) so I didn't add a separate photo for it.

The SA code 807 service sheet is the one WIS says applies to my vehicle, which does line up with why "service 20" tripped for me at 60k kilometers. I really don't understand why there are different change interval recommendations for the same hardware in different regions (especially that 125k kilometers with no time?!?!). I've read other people speculating that it may be legal liability issues with certain countries, though if so, I don't know why I would be higher risk here in Japan. Another thing I was thinking about just now is that my MB software is from 2019 so maybe all this has subsequently been updated and I'm looking at old specs? At the end of the day, I'm going to continue servicing the tranny at 4 years /60k kilometers (assuming I still have it by the next one) as it's not that expensive to do it myself and it lets me sleep a little easier

I have to admit that I'm going to be hypocritical and selective here though because the "including SA Code 807" service sheet also says to change the spark plugs 3 years or 20k kilometers for 177 & 276 engines (8/6 cyl AMGs) while the 4 cyl is 5 years or 60k kilometers. I'm almost certainly not going to be changing spark plugs every 3 years (especially since I don't drive that much annually). I might stick closer to the USA interval of 5 years or 50k miles on that one. I'm also definitely not gonna follow the on pump fuel filter recommendation for "including SA Code 807" that says to change the pump assembly with filter at 5 years or 150k kilometers, vice the USA interval of 12 years or 120k miles. I'm not gonna change the fuel pump/filter assembly unless the pump dies or I get fuel flow issues

I guess it really comes down to me being worried about slow unnoticeable (until it's too late) tranny damage from worn fluid/filter vice spark plugs or fuel pump/filter where I'll likely notice if they are needing to be replaced and there is a lot less chance of them damaging the engine/drive train if they do get worn.

Thank you for the engagement on an older threat!


Tranny change interval for service sheet "excluding SA Code 807" (pictured above) is the same as the "including SA Code 807" service sheet.

USA

Rest of World Low Dust

seamus2154

I think it great to see owners and enthusiast doing this important maintenance. Many people believe maintenance is just oil changes and worn out tires. These cars do so well when taken care of. Brake fluid every 2 years. Trans service, rear differential. 5-7k oil changes NOT 10K. Air filters, spark plugs, cabin filters. Its not expensive...its just knowledge and doing it. Unfortunalty many are ignorant what it actually takes to maintain and expensive car.

S70Houston

Could not agree more!!!!!!

OBR-1

That's not the best way to change the oil. Much better is to disconnect the oil supply pipe and force new oil in through the gearbox. This flushes out contaminants that will never come out by simply draining.

Although they don't officially do this my way at Mercedes, it's the best option. I do it this way.

DanD.

Can someone point me to the right oil and qty for the rear diff?

sn202020

any synthetic 75w85 for rear diff.Or​​​​​​​synthetic 75w90 also works.

seamus2154

This is what I used, and metv the MB spec for a 2018 GLC.
001989330309

DanD.

Thank you both, how many L do I need? Any objections to
https://www.blauparts.com/mercedes-m...RoC4jYQAvD_BwE

​​​​​​​

seamus2154

I bought 3 liters and didnt use all of it? Cant remember exactly how much it took. You fill till it dribbles out, and your done. Ravenol is good stuff.

sn202020

800 ml, I drained & refilled. ​​​​​​​I used Redline 75w85 gear oil​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​ ​​​​​​​​​​​​​​​​​​​​​

DanD.

Can any of you tell me where did you put jack in order to put the front on the stands? Picture will be the best.

rickiteasy

I am not sure what you are trying to do putting the front on the stands. Whatever you do, please do not get under the car with the front on the stands or you might end up looking like Jeremy R. Not pretty.

DanD.

))
I have two pairs of jack stands


I want to put car on all four, i use hitch receiver and jack the back of the car, what about front?
There is only one spot for car jack, this is where I want to put stand.

rickiteasy

I would not want you to be under the car sitting on the four jack stands. Many things can cause these jack stands to fall over. It is not worth the risk of getting crushed. Google Images for "car on four rhino ramps" and you have a picture of how I lift up the GLC to change the transmission oil. I took a nap under there when I got tired without any worries.