StatusQuoReject

Hi I'm at my wit's end with Mercedes and was hoping someone could help me. I have a 2017 C63S coupe (vin # WDDWJ8HB0HF553290) with the A89 frictionless trans & electronic locking rear diff. I'm in San Jose, CA and the Merc dealerships here are just awful. There is no direct line to the service center at the dealerships, they all go through an out of state call center straight to voicemail. I was trying to buy an exteneded warranty & i couldn't get in touch w/ anyone after 23 phone calls over 3 weeks. I took the time out to physically go to 2 dealerships only to wait over 25 min and no one would help me. They just bounced from person to person. While doing all that run around my warranty has expired & I need to do a B service on my car which has 27,300 miles, sadly I lost my job in 2 months ago so I'm not about to pay dealership prices especially given my awful experince with them. I can get even get accurate part #'s or info from the dealerships here.

I used to be a master auto tech at Honda & Acura & i've also worked on BMW's and M cars, so I'm experienced w/ wrenching on cars, but this is my first AMG and it's so hard to find accurrate info on this car. I tried using a Mercedes WIS/EPC service material I bought from ebay & it's so confusing and frustrating. Guess I've been spoiled by Honda/Acura's service manual system which is the best I've ever seen. Leave it to the Germans to make even a service manual overly complex haha.

What I need to know:

1) I'm going to do my own transmission service. Draining the fluid & dropping the trans pan & replacing the trans filter is no prob. I get how to refill the trans at 45 celisus with filler adapter & pump & to shift through the gears & then check for slow drip, but I can't figure out if the torque convertor is supposed to be also drained & if it even has a drain plug & crush washer/seal. The dealership had no idea and so did 2 independent shops I called. The WIS i read (see screenshot below) mentions removing an aux transmission pump and then turning the motor via crank pulley to align a torque convertor drain plug, but when I try to find the part # for the drain plug, it's nowhere to be found. Why does the WIS say to remove the aux trans pump to drain the TC if there is no part # for the TC drain bolt? Does anyone know if the TC is supposed to be drained or not? Anyone had this done on their car? Anyone know the part # for the TC drain bolt & washer assuming there is one?

2) Does anyone who's had their transmisson serviced know if the shop flushed out the trans oil cooler as well? Online trans service kits from places like FCP Euro come with 10L of trans fluid, but the trans supposedly only uses around 6 - 7.5L, so one would assume that the extra fluid is being used becasue the shops must be draining the torque converter and also disconnecting the trans oil cooler return line to flush out the trans cooler as part of the trans service, but no Youtube videos/forum posts/or write ups specify any of this. They all just drain the pan, remove & replace the trans filter & refill, so why the 10L of trans fluid then? Does the trans cooler need to ever be flushed on this car?

3) What rear diff oil do I need & how much? I thought I'm supposed to use Castrol Syntrax Limited Slip 75W-140 Full Synthetic Gear Oil (gold bottle with red pour spout), but someone at FCP Euro said to use 75w85 oil (no brand suggested). Called the Merc dealership & they took 20 min to tell me they're not sure. Why is Mercedes such a joke!?! How can the dealership not know what diff oil their own car uses. Called an indie shop & they weren't sure either. Why isn't it specified in the manual like the oil & other fluids!?! What rear diff fluid are you guys using & how much? Note I have the A89 frictionless trans & electronic locking rear diff if that makes any difference.

4) Does anyone know if you need to use thread sealant on the rear diff fill & drain plugs? WIS says to do so, but only mentions some super rare and expensive German sealant that needs to be imported at $100.

5) What ATF fluid do you guys use? The Merc OEM stuff is pretty expensive here I was thinking of using Liqui Molly TOP TEC 1900 ATF fluid which I found on sale & I believe it meets MBZ 236.15 specs, any thoughts? I know LM is big in the german car scene but whats the real word feedback on Liqui Molly fluids?

6) What's part # for the cabin air filter (the one behind the glove box)? Also which dust filter (the one under the plastic cowl in the engine bay) do I neeed?

I really could use some help and guidance, my car is down until I find these answers & as you can see the dealerships & indie shops have not been helpful. I appreciate you taking the time read this & help. TIA.

Plutoe

whats your point, you posted a copy from WIS all the correct information is outlined that those doc------what is the problem

StatusQuoReject

My point is exactly what I typed from #1-4. It's explained pretty well. To reitterate & simplify...

1) The WIS says to drain the TC, however all forums/posts/online videos don't seem to do this as part of the trans service. Furthermore, when trying to look up the part # for the TC drain plug & washer in the WIS it's nowhere in the trans diagram & the dealership & indy shops can't find the part # either; they also said they don't recall if they drain the TC or not, thus I'm trying to find out from people who've had their trans service, if they know if their TC was drained or not. It's also confusing because trans kits include 10L of fluid, but the trans only needs 7L so that leads me to believe the rest is for the TC & cooler, so eventhough the WIS is stating TC should be drained, the shops I talked to said it can't be serviced. Thus there's a discrepency between the WIS & what's actually being perfomed. Call me crazy but I'd like to know the correct info before taking everything apart & then finding out I need a new TC plug & no one can figure out if this phantom TC drain plug exists or not. It also makes a difference in how much trans fluid I need to buy.

2) I want to know if people who've had their trans service know if their trans cooler was also flushed?

3) I want to know what rear diff oil the car uses. It's not listed in the owners manual & I got mixed answers from the shop.

4) I wanted to know if anyone knows if thread sealant is imperative on the diff drain & fill plugs?

5) Looking for people's feedback on Liqui Moly ATF?

6) Wanted to know part #'s for the filters I listed.

Also the WIS is full of errors and oversights, the way Merc corrects and ammends the WIS as things get updated/changes are made can become very confusing & not all links in my WIS are clickable so I can't get all the specs. Don't why there's confusion about my confusion lol. Have you had your trans serviced & do you know any of this info?

Spicywolff

did you ever get this sorted? I’m in the same boat. How to drain fluid from trans coolers to use the full 10 bottles of fluid.

ChrisHimself

Just punch all 10L through the system and it'll be pretty well flushed if you're worried about it. Do it again as soon as the transmission feels sluggish, you'll know because after the service the car drives VERY differently than you're used to for the first couple thousand miles.

Fill the ATF using a handpump, don't bother with a fancy fluid extractor/pump combo. Slippery Pete on Amazon. The pump literally threads into your quart/jug bottles depending on which one you buy.

You can get away without replacing the drain plug on the case, and not using thread sealer, but be intelligent and check your car for leaks. CAN is the word I'm using. It's your car. I've done it before I became a pro no issues, multiple times. Check for leaks, CAN is the word.

Liquimoly/VAICO/Febi Bilstein/Pentosin are all acceptable fluids. Pentosin/Febi are the cheapest and most readiliy available. Always change your fluid every 30k or less on these cars, the fluid underperforms for it's job on these cars.

Differential oil is 75w-140, spec is GL-5 which Mercedes slaps their approval number on. I'm not surprised 75w-90 came up in conversation, they've been interchangeable in the past. LSD's build insane pressure on the components hence the expensive fluids. I like Amsoil Severe Gear 75w-140 which works with LSD's and is GL-5 spec too. Make sure you buy the special CTA triple-square wrench to get the plug out. Castrol is the correct fill though. 1.25 quarts.
Severe Gear 75w-140

I use Amsoil Signature Series FE ATF, longer service life, fluid stays cleaner and meaner, but it is not MB approved since it is a multi-spec ATF. 100% synthetic, stays cool and doesn't aerate or become sooty over time. It works great in my customer cars. The motor oil is approved by MB and good to go.
2016 C63S Product Lookup

Regarding filters for these I use a Wix for the engine when I'm not using MB Genuine 177 094 00 04. I actually legitimately recommend the Genuine filters a lot of the time. Trust me even if they're made by Mann, the Genuine ones can be different. You wouldn't believe what I've seen regarding car batteries for Mercedes.

I have curated a ton of parts for these exact cars and engines. Use RockAuto.

Oil filter upgrade to the synthetic media, they've been a thing for a long time, Hengst is the OE filter for many AMG's
HENGST E155H01D122
otherwise if you want the paper one it's
MANN HU6008Z

Fresh Air intake filter (the dust one)
DENSO 4536119

Cabin is
MANN CUK26023

PS no dealer I have ever worked at, with, shopped at, technicians I've hung out with have EVER done the TC drain. They don't do it. Does not matter if you have the WIS TSB Mercedes themselves released. Also Mercedes themselves notoriously hate to sell transmission services, even going so far as to not even bring it up. It doesn't pay enough compared to overselling and overdiagnosing small parts that aren't broken.

Spicywolff

that’s a lot of info at once. I’m having the star garage in FL do the flush for me. I’m also having them swap to a weistech pan for the added 2QT capacity and ease of maintenance. Labor is crazy fair with them, so if it takes a extra half hour for them to drain the old fluid from the coolers so be it. I auto cross and HPDE so I don’t want to leave any old fluids in the system if I can avoid it.

I just don’t want to being in 13 AT and be given a lot back, which means lots of old fluid is still floating around.

when they do the flush and filter do they reset the TCU learn parameters? That way trans knows it’s current wear and new fluid?

Trans filter I got the synthetic MB newer style from FCP.

diff lube FCP sold me redline vs castrol. That I should be able to do at home easy.

they will also be doing a coolant flush on my c63S, anything special about that?

jj18

#6. I just had my 2019 C63s coupe B Service completed at MB.
Attached are the part# and price for both the Fine Particle Filter and Dust Filter. I get both changed each year.


Don't know if model year 2017 vs 2019 that it will be the same part number?