Transmission fluid for 1971 280SL Pagoda

[OldGuard60]

I need to add transmission fluid to my Pagoda.  Can you please advise the best option?
Thx

[Pawel66]

Automatic?

ATF Mercedes MB 236.6, capacity 4,75l
1liter container  PN  A0009899203

MB 236.6 is Mercedes norm.

Same goes to manual, actually.

Please note that in the Technical Manual you have the Maintenance schedule that says it all - a good thing to download it and use it in your garrage.

[OldGuard60]

Thank you

[Ed Riefstahl]

I purchased a re-manufactured transmission from Sun Valley Mercedes Transmissions in California, this past summer. Mark instructed me to use Dextron 3 or 4 in transmission. The transmission came half full of fluid from them from bench testing it.

I purchased it from NAPA, if it makes it any easier for you to get. Just trying to help.

Ed Riefstahl
Erie, PA

1966 230SL (Ms Magoo)
1970 280S (Miss Daisy)
1999 BMW Z3 5 speed
1991 BMW 318I 5 Speed
1997 Toyota Paseo Convertible - One of 1000 (have you ever seen one?)
1997 Ford Ranger step side (Mater)
2023 Mazda CX 5

[MartinK]

Hei, ExxonMobil ATF200 (Type A Suffix A) or ExxonMobil ATF220 (Dexron IID). More and more manufacturers stop producing Type A Suffix A and Dexron IID is the next best option. Talk soon. Martin.

[Berggreen]

Hei, ExxonMobil ATF200 (Type A Suffix A) or ExxonMobil ATF220 (Dexron IID). More and more manufacturers stop producing Type A Suffix A and Dexron IID is the next best option. Talk soon. Martin.

I agree with this, and you should if possible not use the newer MB 236.6 grade ATF oils, but stick to the original 236.2, which is equivalent to the Type A Suffix A. The problem with the newer ATF grades is that the friction in the ATF oil is too low for the automatic gearbox in the Pagoda, and you may experience slipping.

I use this classic ATF 236.2 oil, which is made by a subsidiary company of Castrol called Revival: https://www.castrolshop.dk/shop/revival-atf-tq-288p.html

They also make an excellent classic engine 20W50 oil with a high ZDDP content (2200 ppm):  https://www.castrolshop.dk/shop/revival-v67s-20w-557p.html

BR, Christian

[MartinK]

Hei.

I talked to ExxonMobil tech support and lubricant engineering. ATF220 has not totally different friction modifiers and is backwards compatible to ATF200.

In my opinion these high zinc high grade lubricants are not improving anything

Talk soon, Martin

[Berggreen]

In my opinion these high zinc high grade lubricants are not improving anything

Talk soon, Martin

Hej Martin

I think it is generally accepted that the high contact pressure between the camshaft lopes and the valve lifters is a critical wear point in the Pagoda engines - as well as many other engines from the same era with the same design. Here the zinc content in the oil is crucial to avoid excessive wear on the camshaft.

In modern engines the contact pressure is much lower, because of a different valve lifter design. Furthermore, because the catalyser in modern cars cannot handle zinc, different anti-wear ingredients have been used, but adjusted to match the contact pressures in modern engines - not in classic engine design like in the Pagoda.

Whether the engine oil is then mineral based, semi-synthetic or fully synthetic is less important, though a semi-synthetic and fully synthetic oil keep itself clean for longer than a mineral based oil. But few classic oils are synthetic, and most are mineral based.

At least this is my understanding of the engine oil situation for classic cars.

Best wishes,
Christian

[Pawel66]

I am not an expert, so it is easy for me.

As for transmission oil: I use what our maintenance handbook is recommending, which is 236.6. I think experts here wrote it.

As for the engine oil: I trust experts here who worked on these cars for years. They are from the US, which is/was full of muscle cars that had similar oil needs - ZDDP. If the experts here say, pretty unanimously, you need certain content of ZDDP - this is what I need. My only trouble was to find such oil in Europe. I studied multiple product cards of several producers, found out that most of the oils that call themselves "for Classics" are not for classics, they are pretty regular oils with margin doubled, finally found Valvoline VR 1. 20W50, as manufacturer asks. I change it every year, like I was advised here and many other places (by the way, my modern Mercedes does not have anything like "long life oil" - they want oil to be changed every year).

Asking Exxon tech about zinc content (if this is what you asked) is, I think, with all due respect, like asking the Holy Inquisition for their opinion about witches. I trust experts from this Forum.

[Berggreen]

I am not an expert, so it is easy for me.

As for transmission oil: I use what our maintenance handbook is recommending, which is 236.6. I think experts here wrote it.

As for the engine oil: I trust experts here who worked on these cars for years. They are from the US, which is/was full of muscle cars that had similar oil needs - ZDDP. If the experts here say, pretty unanimously, you need certain content of ZDDP - this is what I need. My only trouble was to find such oil in Europe. I studied multiple product cards of several producers, found out that most of the oils that call themselves "for Classics" are not for classics, they are pretty regular oils with margin doubled, finally found Valvoline VR 1. 20W50, as manufacturer asks. I change it every year, like I was advised here and many other places (by the way, my modern Mercedes does not have anything like "long life oil" - they want oil to be changed every year).

Asking Exxon tech about zinc content (if this is what you asked) is, I think, with all due respect, like asking the Holy Inquisition for their opinion about witches. I trust experts from this Forum.

Hi Pawel

Good to hear from you!

In terms of the ATF oils, then here the issue is not about wear, but rather performance. If the friction in the ATF oil is too low, you risk slipping at high torque situations, and if the friction is too high, you loose too much power in the converter. So in the ideal world, you would like to use the ATF oil with the same friction the gearbox was designed for, and this was 236.2 (Type A Suffix A) for the Pagoda aut. gearbox. But it does not harm the gearbox to use a ATF oil with lower friction, thus the modern ATF oils like the 236.6 grade. It only affects the performance. However, when MB or other experts recommend an ATF grade, then I am sure they also take availability into account, and as 236.2 grade is difficult to get now, they recommend what is easiest to get and will not harm the gearbox.

Fully agree with you on the engine oils and ZDDP content. But actually over the last couple of years, many classic oils have become available in Europe with acceptable or high ZDDP content. I did a survey back in 2021, and found these classic oils, which are available in Denmark - but also the rest of Europe. I myself use the Vantage Revival V67^2 20W50 in my silver manual 280SL, because the engine here has never been renovated and always been running mineral oils, and the Motul 2100 Classic 15W50 in my dark green automatic 280SL, as this engine here has been restored, and therefore better can run a semi-synthetic classic oil without risk of releasing oil deposits inside the engine.

Cheers,

Christian

[Pawel66]

Thank you for explanation!

And thank you for the Motul 2100 Classic 15W50 tip (the other one - I would have difficulty getting here). I do not remember now if I saw the Motul one in my research and de-selected because it was 15W50 not 20W50 or I did not spot it at that time. I will take a look at it, but would prefer probably if 20W50 was available.

[MartinK]

Hei,
I do not fear any problems, using Exxonmobil ATF220 in the K4A gearbox. The ATF220 product sheet points out that it is suitable if Type A Suffix A is recommended. That's what the technical support told me on phone either. See here: https://pdfgenerator-east.exxonmobil.com/PDFHandlers/PdfGeneratorHandler.ashx?component=PDS&downloadUrl=https://www.mobil.com/en-DE/Passenger-Vehicle-Lube/pdsdownload/GL-XX-Mobil-ATF-220?p=1

Concerning "Classic" Lubricants I have another opinion which copies the engineers opinion I spoke to. The Pagoda engine family has another important requirement concerning the camshaft lobes. It's not the problem that the lobes and the rocker arms have (compared to modern cars) a higher contact pressure. The problem is the lubrication itself. I have some pictures to explain.

Only the first camshaft bearing is lubricated with pressurized oil. There is a small groove in the camshaft, approximately 1mm wide which provides that the lubricant flows forward into the oil pipe above the camshaft. you can imagine that a cold and sticky lubricant needs some pressure and time to be pumped through this narrow space. See picture with the camshaft.

The second picture shows the oil pipe and the lubrication holes. It is very important to check the holes from time to time. I do that work every time I adjust the valve clearance. You see the same problem: very narrow holes. It is important that the oil can spray out from the first turn with cold oil. The technical stuff I spoke to said that a 20W-50 oil is the opposite than the camshaft needs. The spray holes only are able to spray if the spray medium is not too sticky.

The third picture shows a camshaft bearing. It is not lubricated with pressurized oil. One of the spray holes adds the oil into the opening above. It flows downwards per gravity and needs to build up a sustainable lubricating layer from the first engine turn on.

After you have recognized that the lubrication of the complete camshaft assembly is rather delicate it is not difficult to imagine and to understand that the camshaft needs an oil which flows easy and is easy to pump.

The last picture shows the factory specification for the engine oil for the Pagoda engine family. There is mentioned a 10W-30. I can understand the use of 10W-40 or maybe a 15W-40 but a 20W-50 is in my opinion too far away from factory requirements. I have seen several dead or damaged camshafts, rocker arms and bearings and I say: They did not die due to too less ZDDP. They died due loss of lubrication.

The late production M130 cars had a different camshaft design with a wider groove in the camshaft and an oil pipe with wider diameter. The problem of the camshaft lubrication was well known at Daimler-Benz factory and they tried to improve that with the last generation of M130 engines. But anyway I do not recommend to use 20W-50. But every car owner can fill whatever he wants. I just tried to explain the technical view.


Thanks for reading. Martin.

[Berggreen]

Thank you for explanation!

And thank you for the Motul 2100 Classic 15W50 tip (the other one - I would have difficulty getting here). I do not remember now if I saw the Motul one in my research and de-selected because it was 15W50 not 20W50 or I did not spot it at that time. I will take a look at it, but would prefer probably if 20W50 was available.

No problem, you are welcome Pawel.

I have used the Motul 2100 Classic 15W50 for two or three seasons now, and I am very happy with it. My engine has a tendency to make the oil black pretty fast, when using a mineral based oil. But after I switched to the Motul, the oil stays translucent for much longer time. The semi and fully synthetic oils have self cleaning additives, which makes this possible. The 15W50 instead of 20W50 I only see as an advantage, especially if you start you engine in the early and late season, where it may be below 10C, when you start up. The 15W makes the oil thinner at low temperatures, and thus you get better lubrication at cold start-up. So I am very happy with it.

I would however recommend that you run an internal engine cleaning treatment, with the old oil, before changing to the Motul, so that you remove any possible deposits inside the engine, which may have accumulated during you running the mineral oil without self-cleaning properties. I usually use the treatment from Lindemann: https://lindemann.dk/bil-produkter/oil-system-cleaner-osc/

Cheers,
Christian

[Berggreen]

Hej Martin

Very good points. But I guess then it is a compromise between the high pressure on the cam lopes and not having a too sticky oil to spray and distribute inside the cam bearings.

I guess the main issue with the cam bearings is at cold start, and the problem is less at operating temperature oil, where I guess the 20W50 is still ok., given that you do not have a clocked distribution spray pipe. But at cold start the 20W50 is very sticky, if the engine temperature is below 10C.

This is also, why I prefer a 15W50 classic oil, as you may have seen in my other recent posts.

But I have not seen any 10W30 classic oils with high ZDDP content. So I guess it is difficult to go down that path you suggest, if you still want a high ZDDP content to protect your cam lopes. Or?

Cheers,

Christian

[MartinK]

Hei Christian. Thanks for reply. Again: I say that it is a misconception that the Pagoda engine family needs an excessive content of zinc. To prevent excessive wear current oils are better than this "classic" stuff and  take care that you have a good performance at cold start. Current engine oils with a 10W-40 grade with a 229.3 recommendation (https://operatingfluids.mercedes-benz.com/sheet/229.3) are perfect for the engine. Today there are more other additives to prevent wear than ZDDP alone. ZDDP causes ash in the engine and causes other problems if the engine has a certain oil consumption. As I said, do whatever you think what is right for your car. Talk soon, Martin.

[Pawel66]

Thank you again!

Well, I was told all my life that this "W" stands for Winter. Be it 15W50 or 20W50 - for cold start it is the same, I thought.

The first number suggests viscosity (or whatever this parameter is called) in the normal state and temperature of oil and if the shop says 20, this is what it should be.

In any case - I make maybe 1000 - 2000km between oil changes, so I am not sure how much these small differences matter. I have the late M130, rebuilt.

[Berggreen]

Thank you again!

Well, I was told all my life that this "W" stands for Winter. Be it 15W50 or 20W50 - for cold start it is the same, I thought.

The first number suggests viscosity (or whatever this parameter is called) in the normal state and temperature of oil and if the shop says 20, this is what it should be.

In any case - I make maybe 1000 - 2000km between oil changes, so I am not sure how much these small differences matter. I have the late M130, rebuilt.

Actually, it is the opposite of what you write above.

In a 20W50 for example, the number before the W describes the viscosity of the oil at low temperatures. The lower the number, the thinner the oil and the better the oil’s cold temperature/cold start performance. The number after the W describes how thick the oil is at the engine’s normal operating temperature.

Taken from here: https://www.rymax-lubricants.com/updates/what-does-5w-30-actually-mean/

See also the temperature table in the link.

So with a 50 at operating temperature you can run the car even in very hot weather, as the oil film will still be able to keep contact surfaces lubricated at even very high temperatures without the oil film breaking down and the metal surfaces coming in direct contact.

Cheers,
Christian

[Pawel66]

Yes, you are right, sorry!

[MartinK]

I watched the table with the ZDDP and classic oils. The Viscosity Index is compared to standard 10W-40 oils ridiculous. 

The viscosity index (VI) of a lubricant is the rate of the viscosity change due to a temperature change. To know if a lubricant meets the asset's requirements based on the operating temperature range, you must understand the VI.

If you use oils with a poor VI, its no wonder that you prefer SAE 50 or 60. An engine oil is a matter of different parameters who interact with each other. It depends on the quality of base oils and additives. Class I and II base oils are really basic and poor stuff. Sorry for that.

Talk soon. Martin