mleskovar

"Power flush" is a myth. Think about it. There's already enough hydraulic pressure in an automatic transmission to keep particles in suspension until they accumulate around the filter screen. All the "power flush" does is use the transmission pressure to catch the fluid before it goes into the cooler and replace it with new fluid. Without changing the filter and cleaning the big chunks out not much has been done. Not the first time I've read about transmissions going south after a service. My theory is fluid type was changed and had a bad reaction....or, engine coolant mixed with transmission fluid at the radiator and ruined it. cakris78...what does the workorder say was done at the transmission service and why did they say the transmission failed?

BenzDieselTuner

Wanna go a long time without changing your fluid? try AMSOIL 100% Synthetic ATF

Musikmann

Interesting explanation, so thank you. I am making a mental note of this.

Musikmann

Not to sound offensive DBT, but I think anyone using anything other than OEM recommended ATF in any transmission is a fool in sheep's clothing.

gbahri

I have 104,000 miles on my car and haven't changed the transmission fluid.

alpinweiss

Unfortunately, this is not uncommon on an older transmission that has never had the fluid changed. It is one of the great mysteries of modern life.

If you change the fluid regularly (maybe every 30k miles), it seems to extend the life of the transmission greatly.

If you have never changed the fluid, and have a lot of miles on the transmission, changing it sometimes "shocks" the tranny and dislodges sediment. The sediment then may clog fluid passages, causing internal problems. ATF is highly detergent.

"Lifetime" fluid may mean lifetime of the transmission.

Me? I drive a manual transmission.

wizkid

I think that gets them out of the warranty period for sure.

When I dropped the ATF pan on myC240 last week, I had no visual particles in the filter (I stripped it out and put it to the light). The fluid was dirty but not like I expected after 134,000 miles.

It will be getting another pan drop in 40,000 miles since it is so easy to do and my wife insist on keeping the car until the wheels fall off. Hopefully, I can slide her into a S500 and I can boost the 240 in a year or so.

I had to drop the pan to replace two o-rings that were leaking out a small amount. Enough to make a visual mess. I am glad I did.

See pictures at my site if you are curious.

Musikmann

This report is based on the first 4 oz. drained from the drain pan and with 59,000 miles on my fluid.

From the Comments section:

"We think that this is the first fill of ATF from the high wear and insolubles we found. If this oil hasn't been changed (we weren't sure from the note), we think you should do so now. The high wear metals will make the oil abrasive and create more wear. Insolubles (oil oxidation due to heat, use and blow-by) were high at 0.2%, showing that this oil has been in use too long. The viscosity of the sample was normal for an ATF and we found no moisture in the sample. Universal averages for this type of transmission are based on a run of ~34,000 miles. Check back for another look."

I called Blackstone and spoke with a very knowledgeable and courteous man named Billy. He further explained that my filter had exceeded it's capacity to trap these metallic particles that were floating around in suspension in my ATF. Although some of the individual metals were elevated (Aluminum, Iron, Lead, Manganese and Boron) he was not terribly concerned, stating that the levels were normal considering the circumstances.

I hope this helps,
M

wizkid

That says it all doesn't it. Change now with 59,000 miles. Filter is full. It looks like MB is full of .

Kinda makes you wonder what 134,500 miles has been like on my transmission. I may drop the pan and do another change in 20,000 with filter.

I am going to have to get an test done by those guys.

Musikmann

It sure does in my book wizkid - like you said - the filter was full.

What I haven't posted here yet was that I asked for a transmission service, and all the guy did was empty the drain pan, replace the filter and gasket, and add 4 quarts (possibly liters, invoice doesn't say). The 722.6 transmissions hold 8 liters/8.5 quarts. I think the remainder is in the torque converter, and I have no idea why they call this half-assed job a tranny service. I thought I was asking for a complete change, but I didn't find out what the tech did until he was finished. However, he did confirm that my TC has it's own drain plug.

For what this is worth, Blackstone thinks I'm set for another 30,000 miles after the partial drain/fill and new filter.

mleskovar

After 99K miles wear particles were consistent with the mileage (X3 'normal') and insolubles were only Trace, meaning the fluid was still doing its job. Despite the mileage some of the metals were below average. When they talk about wear particles remember that the measurement is in parts per million. Anything measured in parts per million is not going to be trapped by the wire mesh filter. And when you take a sample it's from the sump....where all the 'gunk' (clutch debris that is not measured) is and before it's filtered and goes through the tranny. So what crap you see when you drop the pan is not damaging the tranny and is normal wear and tear. I think MB is right on about the lifetime fluid and we're just not ready to accept it. That being said, my 'plug' is weeping and I'm getting ready to replace the o rings. Also, I believe they stopped putting the TC drain plug in the 722.6 transmission late 1999/early 2000.
And thinking about it, unless you replace all the fluid an analysis would only be good for insolubles and water. Wear particles present in the TC fluid would show up in the new fluid negating any quantitative analysis.

Musikmann

My 2001 E320 has a TC drain plug of it's own - 2 different M-B dealer's service departments told me that.

Thanks for your elaboration and further information.

mleskovar

[QUOTE=Musikmann;1932308]My 2001 E320 has a TC drain plug of it's own - 2 different M-B dealer's service departments told me that.QUOTE]

So why didn't they drain it? I'd take it back and demand a complete job. I hope my '01 has the drain plug!

Musikmann

Your guess is as good as mine at this point. The Blackstone guy was surprised that they didn't do the complete drain too.

I asked for their "Transmission Service" and that's what I got. It was partly my fault because I didn't specify "complete drain", "flush" or what have you. I think what I received is pretty much SOP for M-B dealers unless we ask for more.

MBTech21

I'd like to see that- must be be some kind of special convertor or something, because the rest of the 01 E320s don't have them. And sadly..this helps prove your other point about service at the dealers...sad but true, it seems..


As far as the fluid- the real change was who was paying for it. The customer is paying again- so 39,000 miles is recommended. Actually, with the number of these trans on the road and the low number of failures- I'd say for most people it is lifetime. Changing it around the 30k mark or so can't hurt, but over 100k and changing it for the first time is a dangerous game.
Mlaskovar has made a good point- the worst thing in the oil is the graphite off the clutches, why don't they check for that? Metal in a trans (unless its big chunks) doesn't mean much.

Musikmann

Hello MBTech21,

It's nice to have a M-B tech contribute here, mainly because you have seen these issues from the inside.

I mentioned the graphite situation (I read the relevant parts of the Star magazine explanation) to my contact at Blackstone, and he said he would place a note in their system

Thanks for your contribution,

MM

wizkid

Can you elaborate? Dropping my pan at 134,500 miles to replace the two orings sounds more like russian roulette than a simple stop a leak.

MBTech21

you don;t drop the pan to change the orings on the connector..it unscrews with a 7 mm screw in the middle of the electric pins..BTW...7000 of those bushings with o-rings on backorder right now....

wizkid

Yeah, but I figured why not and when I removed the plug, fluid ran out like water out of a hose. Well, not that bad but enough to make a big mess on me. With practice and one under my belt, I could probably do it again in under 15 minutes and loose little fluid.

preludejax

I just had my C320/ATF changed. and filter, right away the tranny slip out of gears. I can't even drive it for more then 5 miles..

rmfnla

Yeah, older transmissions often rely on the increased viscosity of the well-used fluid to function.

When you change the fluid out the tranny slips because it is worn and the new fluid will not compensate for that wear.

Sounds nutty but I've seen it happen numerous times.

Ludwig

A trans flush at 60K or 80K is one thing much after 100K is another. Going too long on a "life time fill" can spell trouble when you finally do get it flushed. Our instructors at the Benz training Center in Rancho Cucamonga just kinda smiled and shook their heads as any mechanic would at the notion of the "life time fill."

kjlgpw

At 100k miles my '97 C280 experience a little bit of rough shifting. I talked to my local MB dealer about changing the 'lifetime' fluid and he recommended not doing it. But my local indepenent guy did it for me including a filter change. It cost close to $200 including a differential change. That was 19k miles ago and the transmission has never run and shifted smoother. The improvement I experienced surprised me. Oil is oil right? I guess not. Prior to the C280 I was always a manual transmission driver (BMW's with Getrags) and had little experience with automatics. If I keep the car much longer I will change it again at 150K.

Ludwig

There is something very good about buying the best and taking care of it. Good choice on the trans oil service. Be very careful to use the correct MB fluid.

biker349

my dealer uses a transmission conditioner when they change the fluid. anyone know anything about this? will it prevent the ocassional transmission problems after refill?