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I want to add some clarification to this ongoing thread as I get PMs from more and more members who are DIYing the transaxle and use this thread as a guide. Earlier threads on this topic (before I started this thread) specified the parts shown in the pic below as the parts needed to do the DIY oil change.
The dash 717 part is a DRAIN plug. The transaxle uses this part in THREE places. There are TWO places on the rearmost (Diff) compartment. One to drain the reservoir, one to drain the cooling lines. The front reservoir (the DCT part) uses one drain plug. So, if you're going to follow procedure to the letter, you will need 3 of these.
The -817 part is the FILL plug for the front DCT portion of the transaxle. Frankly, BUT for the engineering standard, this is a completely reusable part as the plug sits above the reservoir of fluid. Same with the rear fill plug which isn't even in the original parts list.
The -90 00 is a tool to facilitate the front DCT reservoir tank that needs to be running and with the temperature target. Frankly, you can do W/O this part too as some members, Katie for one, have made their own tools.
Engineering standards specify sealing devices that use captured O-rings are to be "USE ONCE" so MB had to specify these as replacement parts. Frankly, if the O-ring is in good shape, MY OPINION is these can be reused, certainly at least once on the first change. Since this only comes around every 4K miles or 4 years, even most DIYers will only see this one time. I know Katie has made an argument about the reuse of sealers like this and I agree with her.
So, common sense, if you're doing this job, and the O-rings look good, you'll be safe with reuse. The plug itself is not torque yielded, so it too is reusable.
Hope this helps....
Last edited by Acta_Non_Verba; 09-21-2022 at 08:29 AM.
This is what most are finding here in the US. 20L on the DCT-F3 and 1L on the Spirax.
The MB dealers are all using the 20L containers as it is less expensive when the product is sold in bulk. 20L is too much for one person, of course, but I have been encouraging members to get together and share the 20L. You need 6L to 7L to do the change properly. More like 7L because usually around 6L always drains out and the process is to add one full liter more on the refill then temperature control the loss to get the correct level. So, a 20L could easily be split by two members and almost a third member. The challenge is getting the members close enough geographically to share the fluid.
One thing I thought about is finding 3 members wanting their fluid changed, buy the twenty liters then I could do the change for them. That way the 20L only needs to reach one address.
I bought 20 liter TF and matching 9 liter Spirax.
Now I can do 3 oil changes.
My plan is every 20 - 25tkm. (12.5 - 16kmls)
The gearbox (more the clutch) is heavily loaded. Certainly won't do any harm.
I also have a new unfilled gearbox.
Always be prepared. :-)
All here, car lift, MB filling screw, 8L filling bottle (selfmade, compressed air) and SD.
Also 1 set of new fill and drain plugs. (Waste of money, the "old" then only get new Viton O-rings)
Will not fill in 1 liter more than previously drained.
I absolutely don't get the point here.
My opinion:
If I fill in oil at room temperature up to the overflow (which corresponds to the correct amount of oil), then bring everything up to a certain temperature, it will overflow anyway.
I've thought of the following course of action:
Fill to overflow (oil at room temperature) let the transmission run briefly with this oil and shift through all gears. Then check and if necessary top up again. (Until overflow). Then bring up to temperature and drain excess. Will report.
You don't have to waste a liter of fine oil. And -> save the whales :-)
Miss Hendrik, hope all is well?
Best regards
Stenzel
P.S.
Basically, I let the amounts of oil that I want to determine exactly cool down to room temperature. (I often do this when servicing normal automatic transmissions)
It is more independent and faster to weigh. Impractical for me (I have time, exactly scaled containers, but not an exact 10 kg weight scale) but ingenious. Respect. (Katie?)
Last edited by Stenzel-Germany; 09-25-2022 at 09:03 PM.
You are proceeding on a similar premise that Katie22 does. Katie has written, in the past, that she measured what came out of the front (DCT) compartment, then replaced that same amount in new fluid. I do not see that as a problem if you are satisfied. Both Katie and you are highly technical and have a deep understanding what the operation is and your confidence in the procedure you chose to use will be well thought through as I've come to know you (and Katie too).
I am theorizing here as I know this same procedure of overfilling then allowing the spill over at a prescribed temp is used on many other transmissions including all of the ZF line used in performance cars, that given there will be a wide range of use on these cars, from casual street driven use to extreme track use, that under extreme conditions there will be some fluid loss (Expiration due to heat/friction) in the DCT. I think the factory can offer only one procedure, the one considering the most extreme use. With the condition of extreme use, if you simply measure what leaves the compartment then replace the same, the fluid will be likely be short.
In my case, I do not track my car. It is simply used for pleasure drives and some aggressive street drives, but NO street racing or track. I too thought about, in my personal case, of just replacing what I measured coming out. I know (knew) I would be fine because after I followed the factory procedure, other than a small amount, maybe a couple of fluid ounces, I returned almost the complete liter. I do not believe that would be the same situation on a hard driven track car.
Remember too, as I posted above, this same DCT transmission used in the Ferrari, has a "Fill for Life" maintenance schedule. I am sure there are some Ferrari owners who aggressively track their cars. In these cases, it does not appear there is a special maintenance procedure. I think Ferrari just lets the DCT expire then replaces it new. Or, in their tests they just did not see the need for fluid replacement at all. So it is possible that MB and Ford GT just has fluid change intervals that do nothing but waste precious fluids and makes some maintenance money for their dealers. It is a little bit of a mystery...
18 AMG GTC and 22 F150 Limited. Past owner 16 Maybach, 17 Brabus Smartcar, 06 Ford E150, and 22 G70
I should remind ya all that my car would occasionally do some lurching when you were coming to a stop. It did that from the day in got it with 2000 miles on it. It did this also occasionally after I did the fluid change and bare in mind when I changed it I did the measure exact amount out but I also performed the exact procedures that WIS tells you to do. Months after changing the fluid and dealing with the occasional lurching I decided to add a half a quart of fluid into the trans and to my surprise there is NO more lurching whatsoever. So I can only say that the car did not have enough fluid in it from the factory and following WIS was not perfect either.
I .....Months after changing the fluid and dealing with the occasional lurching I decided to add a half a quart of fluid into the trans and to my surprise there is NO more lurching whatsoever. So I can only say that the car did not have enough fluid in it from the factory and following WIS was not perfect either.
Hi,
I don't quite trust the WIS version either. A GTR driver had the oil changed as a preventative measure at an "AMG Performance Center".
Since then, the transmission "jerks" very slightly when coasting. WIS wrong? Done wrong?
MB is one of the very few manufacturers that builds its own gearboxes. Except for the SLS/GT Getrag. Enemy gearbox? :-)
Idea.
Shouldn't Getrag have an oil change procedure?
Alternatively from Ford, Ferrari. Would be interesting as a comparison.
I understand your comments. I want to make sure and restate the importance of the very first post I made in this thread. The vehicle is presumed to be level (the chassis level) when the fluid changes are made.
In my experiment there I only filled the REAR compartment, the compartment holding the Spirax, with the car on an approximately 4* slope with the rear end lifted on floor jack to accommodate the fluid change. When I leveled out the chassis, I proved an overfilled Spirax compartment by 1/2L.
Although I did not continue the experiment with the front compartment, the one holding the DCT-F3 fluid, That compartment would have the OPPOSITE effect. It would have been UNDERFILLED. Of course, I don't know by how much, but tilting the whole vehicle forward and running through the WIS exactly with the engine running and attaining the correct fluid temp, and capping off, the DCT compartment would lose more fluid than the spec while the Spirax compartment would gain fluid (as I proved).
I am making this argument because when I did my fluid change (on floor jacks) but ensuring I had a level chassis (even when checking for fluid temp while the fill port was opened) it resulted in a properly working DCT. At least I am convinced I have the level correct and I have had no ill effects such as the lurching.
I am sure (in Stenzel's case) that an AMG performance shop would not be changing these fluids on floor jacks, but thought I would add my thoughts.
This reminds me of about 30 plus years ago. Had a friend who owned a Porsche 928. Insisted on changing the transmission fluid himself. Was forced to go out and by an $800 (price then) wrench from Porsche.
My trans/diff service is coming up. With the lack of fluids alternatives (esp transaxle), I am starting to think if I should let the dealer do it or just work with Motul DCTF and get the 20L for transaxle.
I did find this during the research. Ford GT gen 2 uses fluids from Motocraft and made in Belgium. They have the clutch fluid (ford pn: XL-20) and the transaxle fluid (ford pn: XT-75W90-QSC)
Also, Shell Spirax S5 ATE was recommended by Porsche a while back for the older 911s (as recent as 996s) and they did sell them by quarts around $40 a quart. But the fluid has since been updated to Mobilube PTX.
No wonder this is a sticky good job Acta.
Following the transaxle oil change, do I take it easy on the throttle for the next 300 miles / 500 KM (like a break in) or can I just take it to the track after a few miles?
The Ferrari has NO fluid change schedule, just a periodic fluid level check. Since the schedule isn't published by Ferrari, references to the change, or lack of it comes from one of the Ferrari forums. Here is a screen capture from an owner:
On Ferrari, their approach seems to be the old "seal for life" philosophy that the ZF transmissions used to use.
You will laugh, but on actual, published technical specifications, Getrag states:
"The oil of the 7DCL750 is fill for life, which results in considerable advantages in terms of maintenance and running costs." So Ferrari is just following this 'recommendation'
Likely because trends note subsequent bearing seal failure around 8-10 years on Ferrari units, requiring a complete re-build/overhaul, or more accurately, replacement with New/Refurb Trans (Trans is a "non-serviceable" item BS) at substantial end user cost. . .
A form of discouragement by Ferrari, as they do not like aged vehicles running around, or so i hear.
I completely understand. As a Mechanical Engineer with a fascination of the technical aspect of cars, I value my time understanding what other engineers were thinking when they developed certain procedures, (Maintenance, or with designs). For me it has always been not only the "what" (do I understand what to do), but also the "Why" (why did Engineers take this route, why are they prescribing this?). Once I can grasp in my mind the "why" I like to share that part with the community.
After I do, then the "intelligent" community (and I consider you part of the intelligent community) can make decisions to deviate from that process as you've analyzed and assessed best fit your individual needs. I've come to very much respect the expertise you have. It's obvious to me you know what you're doing and you'll make a decision that is rational to the circumstance.
All the Best,
Acta
Originally Posted by Katie22
Acta you are so kind. My first two years of college got me my aircraft mechanics certifications. That would make me one of the people that occasionally grumbles about engineers. Now my husband is an engineer and like you he very often thinks deeply about things. There are times when I have to remind him about the contest between the calutron girls and the engineers at Oak Ridge Laboratory.
Acta / Katie,
This may be a few silly questions, but I've only ever done this before on the 722.9 transmissions (ML63 M157 and G550 M273).
1 - Best I can tell, there is NO transmission filter to change in these cars due to the nature of the DCT (more like a traditional manual gearbox) - correct?
2 - Am I to understand that it is necessary to have the rear wheels off the ground and turning in gear, while achieving temperature of 40C, in order to "shift through the gears several times"? I feel like this could potentially really annoy the car's traction control system etc by seeing differing wheel speeds front / rear. I have a 4 post lift as well as a Quick Jack so I can do this either way, but def prefer to use the 4-post for this.
18 AMG GTC and 22 F150 Limited. Past owner 16 Maybach, 17 Brabus Smartcar, 06 Ford E150, and 22 G70
There is NO filter to change. There is only TWO different fluids to change. It’s been a while since I have done the task but all the directions are in the let’s talk about maintenance section. I followed them exactly however as Acta and I have discussed if I do it again I would simply replace exactly what I took out. Yes you want the car level when doing this. Don’t recall about being in drive but that’s one reason why I said I would just replace exactly what came out in quantity.
Hey all, tackling DCTF and gear oil changes this weekend. Started removing the 4 large panels first to familiarise the locations of the drain/fill plugs. So far so good.
For the gear oil (lubrication oil) drain plugs, per the WIS, there are two of them labeled 1a. The closer one to the end of the car is blocked by a damper and a mount. I am assuming this has to be removed to properly drain from two plugs instead of one? This wasn't mentioned in any posts on the forum. Attached a picture. Yellow arrow is where the mentioned 1a is. Red arrow is the damper.
18 AMG GTC and 22 F150 Limited. Past owner 16 Maybach, 17 Brabus Smartcar, 06 Ford E150, and 22 G70
Yes remove the damper mount if I recall. Also with the one fluid be sure to measure exactly what comes out and reinstall exactly that amount. From there you can if you choose to all the other steps in WIS.
the other fluid is very easy since you fill till it runs out the fill hole.
Hey all, tackling DCTF and gear oil changes this weekend. Started removing the 4 large panels first to familiarise the locations of the drain/fill plugs. So far so good.
For the gear oil (lubrication oil) drain plugs, per the WIS, there are two of them labeled 1a. The closer one to the end of the car is blocked by a damper and a mount. I am assuming this has to be removed to properly drain from two plugs instead of one? This wasn't mentioned in any posts on the forum. Attached a picture. Yellow arrow is where the mentioned 1a is. Red arrow is the damper.
Appreciate any tips/insights.
I am planning this service soon, so I have read up and researched it very well. I believe to have a good understanding, thanks to Katie and Acta's contributions.
Yes, you will need to remove that bracing and damper to gain access to the "differential" side of the transaxle.
So here's the operation:
Lets start with the Differential side (you will need approx 4 liters of diff fluid for this).
Total of two drains and one fill port. They are labeled in WIS. You always start by removing the filler port. So, remove the filler and the two drains. The drain closest to the front of the vehicle is for the system loop, where oil ends up getting trapped during its way in and around the heat exchanger. So, once both drains are opened and fluid is vacated, seal up both drains. Expect around 3-4 liters to be removed.
Now, fill the differential port until it seeps out the fill hole. Cap the filler port. Start car, let idle for 60 seconds. Re-open the filler port, and fill again. It'll take a bit more fluid (likely equal to the amount you drained from the forward drain). Get it? The fluid you filled in the Diff finds its new home in the forward cooling circuit recess. Now, your diff is serviced. Lets move on to the gearbox next.
For the gearbox side, you have a drain and a fill. This is a dynamic level fill, so fancy speak for "you need to have the trans at a specified temp to achieve proper level". Drain and collect gearbox fluid. Measure amount. Reinstall drain once fluid is done coming out. Fill with new fluid, plus one liter. So, if you drained 5.2L, refill with 5.2L - plus one additional liter = 6.2L. Warm up transmission by letting car idle and cycle through all gears (D, N, P, R). Once gearbox reaches specified Temp (60*C), open filler port and allow excess to drain out. It drains "fast" then the trickle slows down abruptly. When that happens, your level is set. Cap off filler port and torque to specs provided in WIS.
In summary:
There are a total of 3 drains and 2 fills in the entire transaxle. Two drains belong to the Differential side. One drain belongs to the Transmission side. Each side has one filler port, respectively.
Tons of info above my post so re-read this entire thread for the details I have left out in an attempt to keep this summary "Broad Strokes". Good luck and let us know how it went for you!
Thanks Steve. I see that you have a GT R as well. I went back on this thread and missed what rwa posted regarding the damper and stacking sequence (argh!).
Overall, the diff fluid (lubrication oil in WIS) 75w90 was a breeze. It came out rather dirty. Drained 2.6L. Filled about the same too before it started flowing out. [Motul 300 75w90]
The transmission fluid (hydraulic oil in WIS) was still quite good, so decided to delay the service. Sampled a very small amount from 2a plug. [Motul DCTF for next time]
Some tips/observations:
There are 4 panels to be removed for the GT R to do both diff and transmission fluid. For just transmission fluid, you can just remove 1 panel.
Removal sequence:
Felt rect panel (just this for transmission fluid)
Fins left and right
Upper diffuser panel
Be careful when removing the fins, there are a few hooks on the upper side. Slide towards rear of car in the direction of air flow. Don’t pull down.
The panels stacking sequence challenge is too real. I spent way too long putting them back together. Make sure you take pictures before removing. I took this pic after putting them back together.
There are 3 types of fasteners once the 4 panels are removed.
Black flange nut x 10
Silver bolt with washer x 17 (two of which are in lower wheel wells, one on each side)
Aircraft mechanic style Phillips screw x 8 (* see Jetpilot718 picture here.)
There is a black metal plate blocking 1e plug from backing out. You can either bend this plate a little or just loosen the e-torx located below.
The damper mounting screws (x2) have blue loctite on them. Reapply as needed with installing.
The transmission fill plug (2e) has M18 x 1.5 thread in case you want to fab your own adapter.
One tool I find rather useful is a stubby 8mm allen key. It fits into tight clearance for 1e and 2a plugs. Search for "Bondhus 8mm Stubby Ball End L-Wrench Tagged" on amazon.
Thanks Steve. I see that you have a GT R as well. I went back on this thread and missed what rwa posted regarding the damper and stacking sequence (argh!).
Overall, the diff fluid (lubrication oil in WIS) 75w90 was a breeze. It came out rather dirty. Drained 2.6L. Filled about the same too before it started flowing out.
The transmission fluid (hydraulic oil in WIS) was still quite good, so decided to delay the service. Sampled a very small amt from 2a plug.
Some tips/observations:
There are 4 panels to be removed for the GT R to do both diff and transmission fluid. For just transmission fluid, you can just remove 1 panel.
Removal sequence:
Felt rect panel (just this for transmission fluid)
Fins left and right
Upper diffuser panel
Be careful when removing the fins, there are a few hooks on the upper side. Slide towards rear of car in the direction of air flow. Don’t pull down.
The panels stacking sequence challenge is too real. I spent way too long putting them back together. Make sure you take pictures before removing. I took this pic after putting them back together.
There are 3 types of fasteners once the 4 panels are removed.
Black flange nut x 10
Silver bolt with washer x 17 (two of which are in lower wheel wells, one on each side)
Phillips screw x 8
There is a black metal plate blocking 1e plug from backing out. You can either bend this plate a little or just loosen the e-torx located below.
The damper mounting screws (x2) have blue loctite on them. Reapply as needed with installing.
The transmission fill plug (2e) has M18 x 1.5 thread in case you want to fab your own adapter.
One tool I find rather useful is a stubby 8mm allen key. It fits into tight clearance for 1e and 2a plugs. Search for "Bondhus 8mm Stubby Ball End L-Wrench Tagged" on amazon.
Hope these help.
Nice addition! About to start prepping for this job (I’ll have some free time coming up in a couple days).
Unfortunately my trusty iCarsoft MBII scanner wouldn’t give me the option to read any life stream transmission temp data (ugh…).
I’ve got a MB 3.0 coming via Amazon that will be here tomorrow to test (I can always return it), but what are you guys using scanner-wise to read trans temp??
09-14-2022, 06:59 PM
