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My take on "lifetime transmission fluid"

23K views 67 replies 17 participants last post by  domwild 
#1 ·
We have lot discussions about fluid replacement. Everybody has his personal preferences. Those who read my replies could figure out, that I am one of the guys, who prefers using the vehicles instead of washing and waxing them.
So my family has Mercedes vehicles with 240,000, 172,000 and 80,000 miles. Having lot of mechanical toys, I tend to neglect the recommended maintenance and prizing dry California weather I am getting away with it. My boat, motorhome, tractor gets oil changes on average 5 years intervals. Brake fluids work for 10 years without a problem. I continue experiment with keeping 30+ years old COMMERCIAL tire on my motorhome.
So getting to the point there are several ways owner deal with transmission fluid refreshing. Some drain 2 qt from the pan, what is about 25% and are happy with it. Some go for flushing, what doesn't change the filter and doesn't clean the bottom of the pan.
I was thinking about it, till Harbor Freight Tools had fluid exchangers for the price I could not refuse.
My general policy is "if you finally do it, do it right" so I went the route with dropping the pan, wiping it clean, changing the filter, putting fresh fluid in it and than do the flushing.
I tried to vacuum some fluid to avoid big splash, but the tube was just gargling. The plug in the pan was overtightened and didn't want to force it too much, since I was doing the job on the edge of my swimming pool, that I filled up last year, so some splash on the dirt wasn't any issue.
I will use this server for pictures, so it might take few steps to go thru all of them.
The pan had some nasty stuff in it. The bottom had fluid, that remind me more of 80-90 oils coming from differentials, than light tranny fluid. Look at the white towel soaked in it.
 

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#8 ·
KAJTEK1; Always look forward to your postings.
Looks like it all worked out for you.
For me? I did a Tranny Oil Change and noticed an Immediate improvement.
I will do it every 2-3 years, NTE 24,000 Miles.
It's for MY peace of mind. I keep a logbook on repairs on my Cars, Bikes, Boats etc and learn what is called for in Factory Maintenance.
I go one better than Factory, either in Quality of Components or the Mileage
point of Scheduled Maintenance.

If your OK with it; heck; i'm OK with it too!
 
#5 · (Edited)
FINAL CONCLUSIONS?

Does the car work better? The non-turbo diesel is still sluggish ;)
Transmission shift differently, what is not necessary better. The converter has much more noticeable slip on it, what makes cold morning shifting slightly smoother. I am driving lot in the mountains, using transmission for braking. Now braking is less efficient. I was satisfy with transmission work before and no change here.
The old filter come pretty clean. I am planning to cut it later for closer inspection. The way I did it seems to be quite efficient (I was a bit skeptic about pushing old fluid with new one without mixing both together). Now the dipstick show quite clear fluid.
IMHO I don't think the hassle of dropping the pan and changing the filter is worth it. Changing the fluid with the machine is easy job and quite efficient. I will probably do the filter on the car with 172k, since I already purchased it, but will probably do just the flush on ML with 80k. ... next year that is.
For proper flushing you need more fluid, than the transmission capacity. Machine eat some for the lines and filter. I used total of 12 qt for 8 qt transmission. Could use probably more, since I stopped machine because it run out of new fluid, while the one on return line wasn't totally clean yet.
 
#6 ·
The gunk in the pan is consistant with what you would expect to find in a transmission that was causing no problems but had a lot of miles on it. The heavy stuff is worn material from the clutch packs that actually accomplish the actual gear changes. Since the transmission clutches are cooled by fluid rather than air like a manual gearbox the clutch "dust" has to go somewhere.

Although there should be sufficient fluid reserves to handle the particle build up well past the point the clutch packs wear out I still believe you will get a better service life out of the transmission if you flush that junk out before it starts to affect the quality of the gear shifting due to changes in the viscosity of the fluid from the foreign particle build-up.
 
#7 · (Edited)
Kajtek - not that you are wrong and I'm right, but I personally would never run a flush machine through any transmission that has a drain on the torque converter. I feel that in order to properly drain the transmission fluid, you must change the filter and inspect and clean the bottom of the pan. If you are going to go that far, then one more drain plug on the torque converter and you're done. Now if I had a car with no torque converter drain, I might consider using a flush machine, but I'd still change the filter and clean the pan. Maybe I'm too old school, but that's my story and I'm sticking to it. :)

BTW, you didn't say anything about adding a pan magnet to your pan. Your car didn't come with one and it would be a good idea to add one. They only cost a couple of bucks.

I also believe that someone, either you or the next owner, is going to pay for the deferred maintenace on your vehicles, whether it be rusted out brake components due to old fluid, failing brakes or a blown tire at the most inopportune time, etc.

Len
 
#9 ·
Now if I had a car with no torque converter drain, I might consider using a flush machine, but I'd still change the filter and clean the pan. Maybe I'm too old school, but that's my story and I'm sticking to it. :)

BTW, you didn't say anything about adding a pan magnet to your pan. Your car didn't come with one and it would be a good idea to add one. They only cost a couple of bucks.

I also believe that someone, either you or the next owner, is going to pay for the deferred maintenace on your vehicles, whether it be rusted out brake components due to old fluid, failing brakes or a blown tire at the most inopportune time, etc.

Len
Believe me I was thinking about pulling the plug on the converter, but first it is a hassle and doing that in dirt pit is not the most convenient, second I wanted to test the machine I was using first time in my life. I have other cars with no plug, so this is testing for the future as well. As I mention, I am satisfy with the efficiency of the flush and as I tried to prove on the pictures, there is no real need for the magnet.
As for "paying for the deferred maintenance in the future". My motorhome is 36 years old. All I am expecting from it is another 20 years. And frankly I don't care if somebody is going to have problems with it after that. The 30+ year old tire is on lift-able tag axle, so even if it blows, all I need is a push of the button to lift it and continue on my way.
Actually I just purchased vintage Airstream trailer with original 1965 tires. I inflated them to 80 psi for test and they hold. Will give them a test drive, before disposing split rims.
 
#10 ·
Back to the original topic, what is your take on lifetime tranny fluid? Leave it alone and transmission sealed up?
 
#68 ·
Merc C220 CDI W204 - Looking at this problem I found out the following: Auto oil "Sealed for life" just means "Sealed away from user, MB only". My service manual says it should be done every 60,000km, probably = 40,000miles. In my case that was not done by Diesel Motors (Perth, Western Australia) at 120,000km, nor at 60,000km by another Merc agent. Sad! Service manager claims it was recommended to user and user declined, rubbish, the invoice lists five other recommendations, like new tyres but not essential oil changes. Diesel fuel filter was also never changed and when I cut it open it showed extensive contaminations. Worse: My MB2 diagnostic tells me the water sensor had failed in the fuel filter, so that should have told the mechanic to change it.

Recommending an essential and compulsory oil change in writing would expose Merc to ridicule plus they make much more money suggesting "optional services", like windshield wipers for AUS$120 or US$90.

Now I have done the fuel filter myself and will do the auto oil also.
 
#11 ·
I'd like to hear what Kajtek1 says is his final conclusion too. One of his posts had the subject "FINAL CONCLUSIONS?" which to me (due to the ?) means he has not come to any final conclusion.

For me, and if we plan to keep our cars past 100,000 or so, I think a transmission service of some kind is better than nothing at all. People have written on other threads that even the dealers have changed their minds, but I think are advising a service at differing mileages. MB will never officially change their policy because that would expose them (I assume in the form of a class action suit) to paying for a lot of new or rebuilt transmissions for customers who "followed the rules" and did not service their trannys.
 
#12 ·
this has been a question for the ages, I have 68k on my mb and think its too soon to change the fluid, maybe at 100k but I want to have a backup plan like trading it in on another MB if things go south after the fluid change
 
#13 · (Edited)
I probably won't get solid conclusion till I do the 172k transmission.
So following up on the 240k. As far as I can say the transmission was never serviced.
I followed up and cut the filter open. It shows some metal shavings, but they are non-ferrous -magnet is not picking them up. Looks like aluminum. The filter on the picture is pretty clean. I just let the oil drip from it so what you see is what it originally collected what is very little dirt. The next picture shows the new fluid after 100 miles. Evidently new fluid washed some dirt from hidden places in transmission on longer drive, since after just a test drive the fluid was way cleaner. Also the exchange had to come with lot of air bubbles that took some time to clear out. I had to add fluid 3 times on the first 20 miles.
At this point my satisfaction with the exchange dropped. The new fluid doesn't look much better than the old one. One more prove that you can't judge oil by its look. I like the result of putting lower-viscosity fluid, what makes the lower power diesel picking up faster, but other than lower viscosity, I don't see why the change would be needed.
 

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#17 ·
Every test is subject to evaluation. I used Blackstone for testing oil on my motorhome.
With 26 quarts we are talking different kind of money here. It come with "no problems" evaluation, so I just spend money to confirm what I already knew ;)
Testing oils can be very helpful when they find silica (sand) in your oil, what will tell you that you have leaks in the air filtering system.
Than you didn't notify Blackstone what MB requirements are for the oil, so their opinion is based on comparing what.... exactly ???
 
#18 ·
...Than you didn't notify Blackstone what MB requirements are for the oil, so their opinion is based on comparing what.... exactly ???

I talked to the lab tech who personally ran my sample but I cannot remember touching on the answer to your question. I think they compare your sample with all of the other samples they have run, and if they are doing their job correctly, should have obtained some parameters directly from Daimler.

However, remember we are dealing with a murky issue here: MBUSA continues to state that we do not need to service the 722.6 transmissions so what numbers are they willing to provide an independent lab, if they are willing to give them anything?

If you are referring to motor oil, MBUSA should be very willing to provide those paramters until they decide our motor oil is lifetime too ;)
 
#21 ·
Musikmann;2757241For me said:
did not[/U] service their trannys.
Thanks for your perspective on the lifetime trans fluid. For me, I will not intend to keep my ML beyond 100K miles or 3 years, because that's when the extended CPO warranty runs out. I prefer not to own a late model MB without warranty coverage, especially when I use as daily driver/18K per year.
 
#24 ·
I understood you and I think the fluid and filter looked good for that many miles. I'm still curious what a lab analysis would look like. My sample looked slightly blackish to the eye (bad to me) but the tech thought it looked normal considering my mileage.
 
#23 · (Edited)
Not making fun of you Kajtek1, I mis-understood what you meant. My point was that no matter how much oil you have, they only require a small sample. I see where you were going with that now.

As to the oil testing sensor, like you I am also skeptical about it. For one thing, every time I add a quart of fresh oil the FSS interval increases by exactly 1000 miles. This makes sense but that makes me mad because what good is my FSS if I have to subtract 1000 miles times the number of quarts I have added?

One of the other points you made is worthy of comment I think. There was an article in the MB Star magazine about the trannys and the carbon content of the components, clutch discs probably. The observation went something like this: Due to the high carbon content of the "clutch components" the transmission oil gets dark and transfers the carbon to the window, through which, the tranny sensor sees the oil. Therefore, the oil is within normal contamination limits but the sensor observes it as otherwise.
 
#25 ·
OK. Let's say I like you and I am willing to spend $25 for sending this oil for testing.
What would you expect from it?
The best scenario for me and worse for you would be results saying the oil is still serviceable. That would mean I have serviceable fluid after 240k and you bad at 60k (?).
Sometimes is better not to know ;)
 
#26 ·
My friend, we are on the same page, and I think my tranny oil was still serviceable after 58k. I think we agree that Daimler has something there; maybe not quite lifetime, but it's good for much longer that my other cars for which the tranny is drained and/or flushed at factory recommendations (Chrysler and Toyota) at every 30k ;)
 
#27 · (Edited)
Let me pull one more card from the sleeve. I bought my 36 years old motorhome 5 years ago after finding it sitting for at least 10 years in the woods. I added some fluid to 30-quarts transmission, but most of the fluid is at least 20 years old. I have easily replaceable filter on it, but with retarder (hydraulic brake) the transmission work much harder than any car can imagine. Still working perfectly on Dino fluid.
Most of my RV driving is in the mountains.
 
#28 ·
A good friend of mine here has a motorhome, but all I know now is that it is 25 years old. He is a gearhead and always tinkering with his vehicles. He has internet and I'll gladly introduce you two if you would like to know him. Maybe you and he could share tips or advice?
 
#31 ·
Thank you for all the info and the burden you took to test the tranny fluid on the one with 240K miles, Kajtek. I learnt a lot from it, but please be careful with real estate ; it has not much to do with technicalities :)

Now, to all others : I talked to 2 service "advisors" from Mercedes Benz dealers and one manager from a foreign car repair shop and they all said that MB do not recommend any change at all. One MB advisor suggested to do it at 35K or definitely 50k, but I could sense he just wanted me to bring the car in and do it to get some money. One other MB indy mechanic told me this : If it ( tranny) sounds OK, works smoothly and does not leak , maybe you do not need to do it , up to 150K or even more. If you ‘re not the type who accelerates and decelerates a lot, and there ‘s no leaking, no “visible” problem, just leave it alone.

heknows
2003 E320
 
#32 ·
I could not get the lead tech, shop manager, and shop forman to agree. The MB line is " sealed for life, as the clutches wear it adds grittiness to the oil and therefore has less slippage", from the training center
The lead tech "when we pull them down they are usually pretty clean unless something was destroyed"
The shop manager "we dont have much experience but the lifetime fill seems to work so far"
The shop foreman " how long do you intend to keep the car? It sure would not hurt after 50/60 K Miles"
I had my 01 E done at 60, pan was clean oil looked good, I rest easier in spite of having an extended warranty to 100K.

I changed the oil at 100K on my 92 S and the trans gave up right after that, MB rebuilt $3500 plus labor $6000 including new lines and things. There was still no grit in the pan, front clutch pack bad evidently common!
 
#33 · (Edited)
...The shop foreman " how long do you intend to keep the car? It sure would not hurt after 50/60 K Miles"
I had my 01 E done at 60, pan was clean oil looked good, I rest easier in spite of having an extended warranty to 100K...
That's almost word-for-word what the tech at my dealer (my salesman recommnded him highly) told me, and that was enough to convince me to have mine done. Like you Peter, I don't think any of the techs or service writers/managers I spoke with at 2 different dealers were in total agreement. Needless to say, that was a frustrating experience but you and I did the right thing.
 
#36 ·
So...can I get a recommendation?

I've got a 2000 CLK 430, with 113K.

It currently runs great and don't think the trans fluid was ever changed, since it's "lifetime."

I am also tending to get the "bang for the bucK" and avoid spending money on service that really won't matter too much.

What you all think?

Also, what do you think about replacing the coolant and brake fluids? My car really does run well and I want to get the most mileage!

(as opposed to my old school of thought, which to no avail, in my opinion, was to follow the service manual to a "tee"

I would say most cars on the road today don't have everything serviced...oil yes, but the rest of the fluids, likely no.
 
#37 ·
If the transmission fluid's never been changed, you need to do so. There's a reason MB got away from saying it was a "lifetime" fluid.

And the brake fluid is hygroscopic, and will collect water as it ages. It should be replaced every two years.

I can't speak as much to the coolant except to note that changing it is simple and cheap, so why not?
 
#40 ·
IMHO I think MB made a huge error of judgement saying the transmission was filled for life. I don't know what their Drive line Engineers were taking at the time. To me it's nonsense and not logical. Any oil degrades over time due to the constant heat cycles and contamination with various wear particles from the component. Also the filters go to about 20 to 25 micron I believe so the sub 20 micron particles will keep circulating and keep wearing things out.

I've also found it's difficult to get a straight answer from dealers in Australia about the subject. MB won't admit they made a mistake. The last dealer I spoke with said every 60,000km or 4/5 years. I've just done my W204 C320CDI at 48,000km at 5 years being an August 2008 build. The car is so much better after doing it and the ATF looked and smelt like it needed to be changed. I also put a third magnet in the pan. It's a Neodymium high temperature rare earth magnet that is extremely powerful. Once on the pan it's difficult to get off. I did the transmission service myself as I've lost faith in the dealers and made a video to show people it's not difficult.

As for brake fluid ... it's cheap so I do mine once per year. Our climate is quite humid and being hygroscopic why not change it often. It's quick to do with a pressure bleeder.
 
#38 ·
Since that topic I bought another 2 high mileage W210 so now we do have 2 of them with over 250k each. The silver Mercedes from original post is gone and I drained ATF from wife car about 3 years ago. The latest purchase at 255k has fluid pretty clear, so I assume PO did some service to it and I am not going to worry about it for some time.
What helps is that the $20 MB ATF is having cheaper alternative from Shell lately,
Coolant and brake fluid. You have recommendation above. I live in area with no freezing and low humidity, so I am usually giving them 5 years.
 
#39 ·
One reason for the confusion surrounding this topic, is that MB advice depends on:

1. The model.
2. The chassis ident

This SI below, issued in 2005, addressed models 203, 209, 215, 230 and advises an ATF & filter change ONCE at 60k km. I presume that this is to remove early life particles from the filter, not because the ATF has degraded.

Note: It states that 'older models are not affected'.
 

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