Transmisson fluid

Your car does not use Dextron. Internet is not much help on determining what equivalent fluid for that specific part number. All I know is that it is a synthetic ATF... and most MB pro said use only that MB fluid and change the fluid every 24,000 miles or 2 years.

Exactly - taking the risk of damaging the relatively expensive trans because of an el-cheapo fluid is ... is... .. aeeeeh... not that intelligent!

Juergen - always using original MB stuff for that

For 1998 E320, my mechanic checked with MB. He said change the transmission fluid for every 100,000 miles. I also checked this on edmuds.com, seems show no need to change it for every 2 years.

My BMW hsa 115,000 miles when I changed the fluid... supposedly lifetime fluid... I'll tell you... it is the worse thing you can do to any tranny... the fluid was dark as used oil and so much sediments there... filter has bypass when it is all clogged up.

So the advice is change it every 2 years or 24,000 miles.

sediments

The theory is that the fluid lasts the life of the transmission. In practice, the makers of the fluid say it lasts a maximum of 100,000 miles. When the MB and ZF transmissions first started to use this fluid it was assumed that a fluid that would be 'good' for 100,000 miles would enable the transmission to last for an acceptable 150,000 miles on average before it wore out. However, they did not factor in the 10th percentile who cover huge mileage in their cars and found a

150,000 mile service life for such an expensive component to be unacceptable. IIRC manufacturers of these transmissions do now indeed recommend a change of fluid at every 100,000 miles. I would change it sensibly sooner, like at every 80,000 miles or so, depending on severity of duty, if one were to have long term high expectations of low costs from ones vehicle. Even then, you should not expect the thing to last indefinately, because it won't.

Huw

The transmission fluid would last 100,000 miles if you could keep the temperature inside the case below 190 degrees F.But studies have shown that the temperature of the fluid can go as high as 240 degrees evening with a cooler installed.Therefore the fluid does need to be changed at least every 60,000 miles,which Mercedes now concurs with.In Dallas we have extremely hot summers so I would even go every 30-40,000 miles here.Same with the oil changes.Mercedes says you only have to change your oil every

10,000 miles or whenever the system in the car notifies you that it is time.Every engineering article I have read recommends changing the oil and filter every 3500-4000 miles or 6 months.Fresh,clean fluids inside make for a happy car.

every

There are no particular problems with engines changed according to the ASSYST system in Europe AFAIK. Certainly, very few owners bother with extra servicing, just as very few bother changing the transmission fluid.

Huw

I wouldn't change transmission fluid at 240000 miles under normal operation either. It's intended to last 100K miles. To be conservative, you can change it earlier, I do mine at about 75K and have never had a trasmission problem in either American or German cars.

I had a GM fleet car and used to take it to Jiffy Lube for oil changes. I'd watch them come in with a piece of white paper towel. They have a smear of fluid that supposidly, and probably did, come from your car and it was light brown. Next to it, they'd have a smear of red new fluid. And they would tell the little old ladies how bad it looked and get them to change it every 30000 miles or sooner.

Well, I had the GM shop manual which clearly stated that it was normal for the fluid to change color and it was not an indication of a need for replacement.

As an added issue, anytime you open up a closed system like a transmission, you also run some risk of accidental contamination with gasket debris, etc. So, I think over doing it doesn't bring any benefit and may actually make things worse.

test

normal

I agree with everything you say. Which is unusual ;-)

Huw

Thanks Tiger: However, my experience with transmission fluid replacement goes back to

1984 when I went from a US built cars and purchased a Camry. The Camry had a drain plug (duh..) so ones a year with one of my engine oil changes I would remove the transmission plug, drain some fluid, add 3-4 quarts of fluid. Castrol dextron sells for about $ 1.75 a quart. So for under $6.00 I would get the extra protection of new fluid. The job is simple, the results good. Sold the Camry with 125K miles...no transmission problems. Bought a 1992 Lexus, which I still own, and did the same transmission fluid replacement routine. Lexus now has 190K miles...fluid looks red, no transmission problems (I have never removed the pan and changed any filter). So now I purchased a 2003 MB E320 and my idea was to continue to replace transmission fluid ones a year (3-4 quarts whatever I drain I replace). If MB transmission fluid turns out to be expensive, I can still replace it every 24K miles.

No Fords huh?

Yep !!

1966 Chevy Malibu 1974 Pontiac Leman's 1978 Dodge Van 1984 Camry 1992 Lexus 1996 BMW 2003 Mercedes

Good plan Mike. I bought my BMW at 97K miles... so I didn't know the history.

i'm not a mechanic and have one do all my work, but my understanding is that the transmission is sealed. at least that's my belief about my 1998 C230...what's the real situation? thanks!

Sherm

No transmission are "Sealed" I don't care how many people said it. I believe the engineers are assuming people throwing out their car after 100,000 miles... so they figured no tranny fluid change is good enough.

Let me put it this way, even though tranny are not as dirty as engine, would you consider not changing your oil for 50,000 miles? I wouldn't think so, so why should tranny be an exception?

Just because there is no drain plug doesn't mean it's "sealed".

Replacing the fluid in this case would simply mean pulling the transmission pan and probably replacing the filter while you have it off...

I think every 75,000 miles is good enough personally.

My 190e had just had this done when I bought it (110,000M) and the tranny seems to work right, so I am not going to be doing this too soon :~)

Marty

Your comparing apples to oranges. The principal engine oil contaminants come from the byproducts of combustion, which are totally absent in a transmission. The recommended change interval for engine oil has absolutely nothing to do the change interval for transmission fluid or antifreeze, or anything else for that matter.

I have nothing against changing fluids somewhat more conservatively than the manufacturer recommends. But I believe 24K miles in normal service is just a waste. Even Jiffy Lube only recommends it at 30K and they are trying to do it as frequently as possible for business. And to top if off, we've got some posters here with the roll your own strategy. Instead of following the manufacturer's advice to change fluid and filter at appropriate intervals, they propose just changing the fluid very frequently and ignoring the filter all together.

I'd love to see a source for data that shows such frequent changing has any benefit.

thanks for the advice, guys. I've got an FSS interval coming up at 81,000 + miles. the car runs great and I want to keep it that way...