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Guys, since my SL-500 2004 came from a careless previous owner, I have been doing all preventive maintenance I can on key areas. This time I am trying to change the transmission oil, and have watched several videos, and seems like the only way is by removing the pan and pumping new oil through the drain plug. My question is, how you measure if the amount of fluid into the unit is low or high?????
Does anyone know the drain plug thread size?
If it is a 722.9, which I believe it is, there is a standpipe in the center of the plug that sticks up into the pan. When the car is level snd running in park at 100 degree or so transmission fluid temp, removing the drain plug will allow the correct fluid level to be reached because it is at the level of the standpipe
The standpipe is a plastic tube that is threaded inside of the drain plug, I believe it takes the same size Allen as the plug to remove. When you pull the drain plug and the engine isn’t running, a very small amount will come out. After removing the standpipe the rest will drain.
I would suggest measuring the amount that comes out and putting that much back in. It will probably drain about 3.75 qts at a time. Yiu will probably need to drain/ fill at least 3 times to get the fluid looking decent. I use a pump for a marine outdrive to fill the trans. It’s time consuming and a real pain if you don’t have a lift, which I do have.
2004 SL500 should be the ‘easy’ 722.6 transmission. Go to FCP Euro and get this kit: https://www.fcpeuro.com/products/mer...-kit-722-6fck1
Look for videos on servicing 722.6 tranny. The refill point is between the engine and firewall slightly on the passenger side. Look with a flashlight and you’ll see the small cap. This is a pretty easy service.
Wings, thanks for the tip but unfortunately it won't be that easy. The transmission is in fact a 722.9. The SL-55 still has the 722.6 since it is believed that will handle more torque!
CDK, I started the process to change the tranny oil and found the following:
When removing the plug, about half gallon of fluid came out. Now, after reviewing all info, the fluid should be levelled to the top of the filling tube inside the pan, so theoretically, when removing the pan plug, no oil should come out if the level was right. Also, after measuring the total oil extracted it was about 1.5 gallons. Does it makes any sense????
No it must be running and to temperature when removing the plug to check. When it’s not running, it will be higher, like when checking a transmission dipstick it needs to be running.
Sounds like it was overfull by almost a quart and a half or so. I would put 5 quarts back in and get it to 100 degrees or so and check it. Was it black
I am refilling with Valvoline Maxlife multivehicle ATF. The application sheet states that it meets 236.14 and I called their help line and the tech assured me it will be fine!
There is a guy in older forums (Glyn M Ruck) that had an ample discussion on ATF's. He seems pretty knowledgeable on the subject.
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That fluid wasn't designed to work on your trans. The only rationale behind qualifying it is reverse compatability. Guys use to try that with older 5 speed autos.
Yes it is trans fluid. Yes you have an automatic trans. Yes almost all fluids formulated for cars after 2000 could be used , but why change it if you're going to use low grade fluid not specifically designed for that car then? What type of filter/gasket are you using a Chinese copy?
The transmission in these can cost $5-7000 now. Maybe you won't have any problems but I wouldn't bet on it
Good Luck
Hary, thank you for seeding that worry on my mind..!
When choosing this ATF I called the Valvoline help line and quizzed the tech. He assured me that, as they post in their data sheet, it meets 236.14. So, I don't trust the seller but have to thrust the manufacturer..!
Now, I got one more question for the experts....I have owned American Cars and trucks as well as European Vehicles. Those older models have a dipstick and the dipsticks have a "range" which we call "tolerance". Now, I was reading the post of a guy who recommends to level the transmission pan to +/- 1 degree, then he states that the oil must be at 45 C. and he really meant it since he recommends to use a high end thermometer! Common guys, every thing in life have a "tolerance" nothing could be maintained to the perfect target! I wonder what is so special about these transmissions that the oil level must be "perfectly" controlled.
45 C on the fluid tells me I need to control the oil thermal expansion, and the level assures that the internal level of oil inside the pan is "perfectly leveled". I noticed that the drain in just in the middle of the pan lengthwise, so the oil spilled over that tube would be the same within certain range of inclination. Chances are that the transmission will leak some oil with time through the front and rear seals and that perfect level won't be as perfect!
For what I read on other posts including other MB models using the 722.9 tranny, they have not have any issues due to ATF fluids!
So, in my humble opinion, it is good to be careful, but sometimes the Germans go too far to make sure their products performs well.
Max life is fine, as easy as it is to change fluid I drain the sump in mine every other oil change. It’s usually about 3.75 quarts in all the transmissions I own. I put back in what I take out. Keep in mind if you follow Mercedes original maintenance schedule, it was a sealed unit for life. Didn’t work too well for making the trans live.
That fluid wasn't designed to work on your trans. The only rationale behind qualifying it is reverse compatability. Guys use to try that with older 5 speed autos.
Yes it is trans fluid. Yes you have an automatic trans. Yes almost all fluids formulated for cars after 2000 could be used , but why change it if you're going to use low grade fluid not specifically designed for that car then? What type of filter/gasket are you using a Chinese copy?
The transmission in these can cost $5-7000 now. Maybe you won't have any problems but I wouldn't bet on it
Good Luck
Max life is fine, as easy as it is to change fluid I drain the sump in mine every other oil change. It’s usually about 3.75 quarts in all the transmissions I own. I put back in what I take out. Keep in mind if you follow Mercedes original maintenance schedule, it was a sealed unit for life. Didn’t work too well for making the trans live.
Which maintenance schedule are you referring to, regarding the sealed unit for life?
Directly from Rodney, I would guess this is good info. Manufacturers recommendations aren’t always in the best interest of keeping a car running for years to come. As has been stated many times before, “any new grease is better than no grease or dirty grease “
Gents, 10 years ago was a interesting discussion on other threads about the same subject. I am copying below an answer from Glyn M Ruck, who seems to be a very knowledgeable guy:You have to respect the fact that I'm on this forum in my private capacity & can't post proprietary company information. I can only post information that is in the public domain. I'm more than satisfied that I've done my homework. I certainly agree that there is a HUGE amount of crap that is spoken on the internet. I'm pleased to say that my credibility on this forum is sound & you are welcome to search for my numerous posts on transmissions which contain a large amount of detail & on many other subjects.
Please understand that the 722.6 is a million kilometre transmission if run on the correct fluid & serviced every 60,000 Km's. Many Taxis in Asia have achieved this & we have an E240 in Cape Town at the office with 800,000Km on the clock that does airport service & has had no major repair. The only thing ever touched on the transmission was the electrohydraulic bushing O Rings leaking - common problem, US$8 buck part & external replacement. There is a TSB on the issue that I can post if you are interested.
In the modern Auto transmission the biggest single challenge for the fluid is to have the correct blend of very high quality friction modifiers that allow controlled slip & final lock up of the clutch packs & TC clutch in the transmission. Too little slip & you suffer shift shock. Too much slip & the clutches take too long to lock up with severe heat generation & resulting damage to the friction material used. All manufacturers use different friction materials & lock up pressures & thus require a fluid with the correct frictional characteristics to make the multi-wet-plate-clutches operate safely & correctly. In the days of pressure, vacuum, speed actuated transmissions if you put GM fluid in a Ford transmission it would fail in 5000 miles. Ford & GM have since unified their spec. The next challenge for the fluid is to provide controlled shift shock over the service life of the fluid.
You can never have a transmission changing more smoothly than it did new with the correct fluid. If you use a non approved fluid that suddenly makes the transmission change more smoothly than a new one with the correct fluid you are on your way to trouble & a failure sooner or later. Smoother change than design is a sign that the fluid is allowing too much clutch slip which leads to overheating & wear of the friction material. The whole thing is a balancing act.
Now you get some OEMs that design a transmission, like Honda, & then say to the oil industry now design us a fluid that will make this thing work & we want no shift shock. Yeah right! I'm sure some reading will inform you of all the trouble they had in the early 2000's. They have learned.
Benz has a different approach & works with the oil industry in the design stages to ensure that fluid and transmission are designed to work together from day one. Then they have a continuous improvement process with the industry as better synthetic base stocks & additive components become available - hence steady improvement & longer fluid life in service from 236.1 to 236.14 and beyond.
Benz does not publish fluids that fail testing. It sends the oil company back to do their homework. Valvoline has many products approved by Benz. It does not have a transmission fluid approved by them & that might be because they never submitted samples. One thing I can tell you, however, is that if Maxlife is suitable for Ford & GM transmissions, it is not suitable for Benz. The frictional requirements are quite different. Benz fluid similarly is no good for Ford & GM transmissions.
We have tested a whole range of these so called "multipurpose" ATF formulations in our research labs & they are all a horrible compromise & certainly don't pass the Benz specs & requirements.
Sound judgement tells one that you should use a product that is approved by Benz from whichever oil companies take the trouble to get it through the rigorous testing regime. Benz does not make money out of the approvals process. It costs them money.
Remember that the Shell fluid costs < $6 a quart. That is a damn good price for a fluid that is damn expensive to formulate. No one is suggesting you buy from a rip off dealer & BTW some US dealers sell at $7 a quart so they are not all robbers
On the other hand I am attaching a segment of Valvoline Max life spec sheet. Then I wonder if during the last 10 years they did something to be able of adding this spec to their product.!!!! Any Comments??
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When it comes to oil and filter change on Mercedes automatic transmissions there is one thing i for sure will do and that is to replace the transmission filter using an original transmission filter and original transmission oil from Mercedes
As as some have written here in this thread is to also drain the converter since it holds a lot of oil. Almost as much as the transmission.
Before doing this work i would like to have a spare converter drain plug as well
The first time i replaced the oil and oil filter on a Mercedes several years ago i did not use the original filter and oil and the result was that about a couple of weeks after the transmission oil and filter change the automatic transmission started behave like it had a worn clutch on a manual car. The 3 gear was the worst. I did use quality oil but that did not help,
The automatic transmission was operating silky smooth before the oil and filter change. So the reason why i did replace the filter and oil was just regular maintenance work on the car
Just an example : If you have an main seal oil leak i would never use any seals other than original Mercedes parts to replace the seal. There is so little money to save on parts like this.
After that i have always used original Mercedes transmission oil filter and original Mercedes automatic transmission oil and never had any problem
Last edited by TheSaint; Apr 14, 2022 at 12:23 PM.
Just an example : If you have an main seal oil leak i would never use any seals other than original Mercedes parts to replace the seal. There is so little money to save on parts like this.
My Indy told me when we were suspecting a rear engine seal to let him buy the seal from a Parts Store (think it was Advance or Auto Zone not sure which) because if the seal fails they will pay him for the labor to replace it. So with that assurance a Mercedes Part might be less than advantageous. I did buy a new plate which holds the seal and one-use bolts for the job that never happened.
Last edited by Gene Fiorot; Apr 14, 2022 at 05:24 PM.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
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