JeffreyP

Personally, flushing fluid is the easiest part.

You can get the indie/dealer to do the partial drain, change filter and clean up the pan.

Afterward, you can follow multiple sticky diy procedures to flush fluid using the cooler line. For me, the easiest one to get to is the flexible hose that attach directly to the radiator. It only take me about 45 minutes to do so. It may look different from car to car, so do your research.

Regards,

Glyn M Ruck

[QUOTE=JeffreyP;5040109]MB writes the fluid spec including ideal viscosity range. It has not changed. MB contract out their genuine brand fluid manufacture to competent oil companies.

The european taxi industry has typically suffered failure of the first to second one way clutch at about 700,000Km from too many high torque changes in that application.

People don't understand what they percieve as a problem. They don't understand desired clutch lock up & transmission adaption either automatically or with a star. I've explained what an over smooth change can mean - too much slip.

Glyn M Ruck

It's amazing the way these "old wives tales" have pervaded NA.

Find a decent Indy that is prepared to listen & take him a copy of the WIS instructions I posted. This is not difficult.

See C230 Sport Coup's thread. He has done a number of flushes on 722.6's himself. He also thought the 236.14 fluid made for crisper change & then it adapted & was fine & he has the old non-flashable TCU

https://mbworld.org/forums/c-class-w...c+transmission

splinter

^ Although Mr. Ruck and I may have differing views on various issues, tribology isn’t amongst them.

The man has made a successful career of advising manufacturers (and his company’s petroleum engineers) on proper lubricant blends. He knows of what he posts.

Disclosure: I’ve used 236.14-specification Shell 134 and Fuchs 4134 during my various DIY 722.6 & 722.9 fluid renewals.
Absolutely no trouble thus far. Beat on ‘em pretty regularly, too. Knock wood.

Of course you're free to use whichever ATF you’d like. :y

LILBENZ230

You don't recommend using the approved fluid in the 722.6 transmission? I have a 2005 C230K with the 722.6. It now runs the 236.14 fluid exclusively, but I did just a fluid change instead of a flush at 100k miles and so between 100k and 120k miles my car ran a half/half blend of the 236.10 and 236.14 fluid. So if we're going by anecdotal evidence = proof, then my car is proof it won't hurt it, no? My shifts were smoother with a half/half blend of the two fluids than they had been before the change. And smoothed out even more when I went to a full 236.14 capacity. They're not too smooth, however.. Too smooth = too much slip = heat = enemy.

At the time when my car was built the 236.10 fluid was the current fluid. Times change, improvements are made. The 722.6 continued to live on, as I'm sure you know - in the high powered AMG cars - for a time. As a matter of fact, I think the 722.6 may still be used in some cars to this day. Do you really think that Benz disregarded this transmission altogether when approving the 236.14? I think not.

If you don't want to use 236.14 in yours.. hell, if you want to use off the shelf generic ATF in yours.. that's fine. But don't try to persuade others into that. Transmissions are expensive across the board but really very much so with a Benz. Sticking to Benz recommendations is the way to go.

grane

This was exactly the procedure my technician used when he changed my G500 and CL55 transmission fluids. How do I know? I was the assistant who ran and stopped the engine while on the lift! Now I know what he was doing underneath the car and why he was using the hand pump. I know that he used at least 10 bottles of the .14 fluid on the CL along with the filter change, a new gasket and the magnet clean. The drained fluid at 40k miles was very clean and clear. I use the 2nd gear start, Comfort Mode on the CL, because a little AMG bird whispered in my ear it is best for the longevity of the 5 speed and, given the torque and power of the Kompressor engine, even sporty driving does not require and maybe even enhanced by 2nd gear starts.

I came to find out that some dealerships do not want 2 techs working on the car so they only do the " drop the pan and put in 5 bottles" partial method.

mis3

First of all, since some of our transmissions have no drain plug, they will need a special machine to fully flush the fluid. There are other ways to do the full flush like through the cooler line and radiator hose as suggested by some members here.

Also, someone mentioned that when asked why they don't recommend a
complete flush and replacement of the ATF, he was told that this may cause problems in a high-mileage transmission since it loosens and moves debris around in the transmission, etc.

Glyn M Ruck

Good for you. That is the right way. Especially with the AMG - the higher the torque output of the engine, the greater the stress on the transmission. Of course with the 722.9 the flush is not necessary but then they must drain the converter via it's drain plug that post 1999 722.6 transmissions don't have. If your fluid came out looking good you are obviously a civilised driver.

By far the vast majority of 722.6 transmissions on this board are on the w203 forum due to numbers sold. Many of course are 4 cylinder models with M111 or M271 engines which don't stress the transmissions as much as the larger engines. splinter has a C32 which gets tracked from time to time & enthusiastically driven in general.

I do, however believe that due to the generally younger demographic driving the W203 that some of the cars are driven very hard.

LILBENZ230

As Glyn pointed out, this is mostly an old wives tale. Now, if you were driving a Honda, I'd be inclined to agree with you. When I had an Acura TL and was active on Acurazine it was not at all uncommon for those transmissions to fail after being flushed. But those transmission had inherent design flaws. The 722.6 does not. I flushed mine at 120,000 with no issue.

Glyn M Ruck

Read the second WIS flush document. You do not need a special machine. You need a little hand pump.

There should be no debris in the transmission beyond the filter. Note sensible caution in the WIS document regarding cleanliness. This applies to working on any transmission or hydraulic equipment. You need to be sure you don't introduce dirt. Anybody accustomed to working on transmissions understands this.

As it is obvious that you have a level of concern about this service not helped by certain comments on this thread, I will give you a compromise that while not ideal will give you about 80% of what you are trying to achieve.

Do the half change with filter at the dealer with 236.14 fluid. Examine the used fluid filter. If it IS NOT full of wear debris then drive the car for another 5000Km & drain the oil again from the pan drain plug. Do not remove the pan or disturb the filter a second time and merely refill the fluid to the correct level at the correct temperature with fresh fluid.

This will give you a reasonable level of fluid replacement.

While not ideal it is better than your present situation. One of the only problems is that mixing oxidised fluid with new fluid catalyses oxidation in the new fluid & shortens it's life. (like putting crap in ice cream)

Forget all about old generation obsolete fluids.

Good luck

Rudeney

Even if you decide to pump out all the oil via the cooling lines, you should still change the filter.

mis3

[QUOTE=Glyn M Ruck;5041535]
Do the half change with filter at the dealer with 236.14 fluid. Examine the used fluid filter. If it IS NOT full of wear debris then drive the car for another 5000Km & drain the oil again from the pan drain plug. Do not remove the pan or disturb the filter a second time and merely refill the fluid to the correct level at the correct temperature with fresh fluid./QUOUE]

This is a reasonable compromise.

For the last ditch, I did ask my MB SA to ask the parts manager to call if he can get the old fluid. My reasoning is that thenold fluid has worked well in my car for so long so they must be save.

if he fails i will use your plan-B. For 2nd flush, i do not have to change the pan and filter, right? During the first flush, do i have to ask the tech to watch for something or do anything special

Glyn M Ruck

+1 - absolutely if I have not made that clear.

Glyn M Ruck

[QUOTE=mis3;5042727]We are all different. I could not wait to get the new fluid into my C240.

Plan B:

Change 1: Drain fluid, drop pan, change filter, clean magnet in pan, fit new gasket & refit pan. Replace pan plug with a new crush washer. Fill with 4 or 5 quarts of new fluid to the correct level using Star for temperature reading & a service dip stick. Work cleanly at all stages. Examine used filter for excessive debris. Nothing else special.

If no excessive debris on filter.

Change 2: Remove pan plug & drain fluid. Replace pan plug & crush washer. Fill with 4 or 5 quarts of new fluid to the correct level using Star for temperature reading & a service dip stick.

If there is excessive wear debris on the filter then repeat Change 1 again rather than Change 2. i.e you need to change the filter again.

Good luck

I would rate this as severe wear debris.

mis3

For Plan-B, if the idea is to put in more new fluid, why not do the 2nd partial flush right away? More specificially, do the 1st pan flush, run around the block for 5 minutes, then do the 2nd pan flush.

Is the 5-minute run time suffice to mix the 2 fluids thoroughly?
Should the filter be changed again after I do the 2nd partial flsuh right away?

Glyn M Ruck

Yes - you could do them back to back. I would try and put on about 5 miles & run up & down the selector including reverse so that ALL circuits in the box are flushed.

No need to do 2 filter changes unless the filter is found to be in a bad way in Change 1.

mis3

Well, my SA called me back and told me that the parts manager tried but could not get the old fluid. The parts manager even guessed they were the same fluid but from a different supplier.

I mentioned Plan-B and he said I was crazy. He would go along with this but I would have to pay for the transmisison service twice. He said the only saving was the filter. He kept asking "Why, why, why..." and he still maintained his position that the ATF for my car was "lifetime".

I really have to get a local indie for my car.

lars

Or maybe another dealer. I talked to two dealer service writers in my area and both told me the recommended fluid change interval was 60K km. One of them changed mine last month. I have a couple of older cars I do all the work on myself, but this service seems to offer enough chances to make a mess that I'd rather pay someone (it wasn't that much) to do it for me. I must be getting old

JeffreyP

Changing fluid with back to back drain (and new fluid) is not a bad idea as I have said in another thread, it's better to do complete flush with new fluid than not doing anything at all. However - you should drive around a bit say 30 minute after the initial one, so more of the old fluid can be pump out of the torque converter.

Here's an interesting test on fluid compatibility for you. Siphon out some of you old ATF, mix it with some new 236.14 fluid (say 6 oz each). Now heat it up and stir vigorously for a while (simulating the tranny action). Leave it overnight, see if the fluids separate. To me, if the two fluids don't mix, blend together then it's not beneficial to do a partial drain with new/different fluid at all.

JeffreyP

Yours is a success story using 236.14 in 722.6, but there are also stories of problems using 236.14 in the same tranny, so to me it's a toss up. The argument I am making is that I haven't heard of owners using 236.10 spec fluid complaining about their transmission problem. Mr Ruck said that the European MB Taxi industry has tranny problem, but from his latest correction, it's not fluid related.
If you read the link I sent, there is a gentleman (Eric++) who look over 30 MB shops in China and he's seen enough problem with 722.6 tranny using 236.14 fluid. He will not allow any of his shop mechanics to put the new fluid in any of 722.6 tranny.

To me 236.14 is designed exclusively for the 7-speed tranny (722.9) but somehow being thinner and of different properties will magically be backward compatible? Hmmm.

Glyn M Ruck

Yes - well you & others don't know what you are talking about. A little knowledge is a very dangerous thing.

Do you honestly think that Benz would mandate the use of a non compatible fluid & use it as initial fill in the 722.6 on all W204 diesels etc. up until 2012 as an example?

Please feel free to do your kitchen table cook-up & stir crap. You will find they mix just fine.

BTW - I have not made any corrections. These are a figment of your imagination & your inability to correctly construe matters technical. Use of 236.14 fluid has increased the life of the first to second one way clutches in Taxi service on the 722.6.

Get it into your skull. The old product is obsolete & you do not know better than Mercedes Benz.

Glyn M Ruck

Tell your SM that even in a wonderful country like Vietnam they know it's not filled for life.

Ask him to phone his counterpart at Cycle & Carriage in KL, Malaysia. He will tell him to change every 60K Km's.

Your SM would be fired in SA for saying something like that & violating the WIS.

You either need to find a competent dealer or go to a good Indy.

BTW - he should give you a reduction in labour for the second change. Not having to drop the pan saves quite a lot of time.

Here is the old MB 2006 lube chart from Vietnam when 236.10/236.12 were the top of the range fluids & the 5 speed could use either & the 7 speed required 236.12. Note change interval. (In fact for a while the 7 speed was run on 236.10)

mis3

Let's agree on the difference of opinions on the fluids. One thing we all agree on is that the ATF is not "lifetime".

To be fair to the SA, he just repeated what he was told by the mothership.
He is not a transmission specialist nor an oil specialist. I am doubtful if there are too many SA that would understand the internal working of a transmission.
Even with a remote chance that he has an opinion of this very topic, he cannot say anything to the customers. All he can do is to notify MB Canada of his findings.

Glyn M Ruck

Why are other Canadian dealers getting it correct as in lars post? I would bypass the SA & only talk to the Service Manager. He is supposed to be the most technically competent person in any MB dealership.

mis3

Last transmission service I did by the dealership, they also changed the following items on top of the ATF and filter:
140-271-00-80 Oil pan gasket
140-271-00-60 Seal ring
140-991-00-55 Pin

Since probably an indie will do this job, I will monitor the whole process. Should thes parts be changed at the first partial plush? The 2nd partial flush?