etownbala

So I know at first Mercedes insisted that our transmission oil is in a sealed unit and does not need to be changed. I've also heard that Mercedes later put out a communication to owners changing that to once every 100,000 miles. Can someone clarify for me? I am approaching 100,000 miles (86,992 miles to be exact) and am wondering about pricing at the dealer, what oil to use, whether this is a diy job or whether it should be changed more often then once every 100,000 km???

Thanks in advance.

KRis

gregory13lil

I personally recommend that you change the trans fluid now. There is and never will be a real lifetime fluid " at least not in my lifetime". It is a DIY job as long as you have access to a lift or a way to get all 4 wheels on a jack, you will also need to buy a transmission dip stick (40 on ebay), transmission filter, trans pan gasket, trans fluid and some good beer. I suggest you use the dealer fluid but there is an mb spec trans fluid that can be used as well, red bottle but can't remember the name.

etownbala

Thanks for the reply! Why the transmission dipstick and pan? Do these items get damaged or are one time use only?

gregory13lil

Our cars do not come with a transmission dip stick installed, the transmission line only has a red cap on it. The dipstick is used them removed because it's way too long, after removal you place the red cap back on the line. The pan is not replaced, you need to replace the trans pan gasket.

etownbala

Hmmmmm ok. Still not 100 percent on what the dipstick is used for...just measuring the level when you put the new oil in? Sorry for the questions just unsure of the procedure...no info in search on diy...

KRis

gregory13lil

Correct, the dipstick is to check the fluid to make sure it's not too low or too full. Both can damage the tranny. Without the dipstick you're just left guessing and you don't want to do that. It's not a simple change because some fluid may still be stuck in the transmission bell housing.

etownbala

I have a air pump fluid extractor that I use for changing my oil. Would I just be able to throw that down the dipstick tube and suction out all the oil and then just pour back the new oil? Thus saving myself raising the car and buying a gasket...i would obviously still get the dipstick.

KRis

MarcusF

The filter would still be dirty and the pan magnet would still be covered (if covered).

gregory13lil

Exactly as said above, thanks Marcus!

Oh..I also found you a dipstick for 15 bucks on Ebay: http://www.ebay.com/itm/Mercedes-Benz-722-6-Transmission-Fluid-Dipstick-Repair-Tool-1220mm-140589152100-/281220638218?pt=Motors_Automotive_Tools&hash=item417a0e660a&vxp=mtr
Greg

etownbala

Ahhhh ok makes sense. Silly me. Thanks for the info guys...im going to give this a try since they quoted me in the neighborhood of $350 CAD to perform this service.

KRis

etownbala

Anyone have anymore info on recommended fluid? Is there anything I should look for when I open the transmission up?

KRis

Serndipity

The subject of transmission oil service has been thoroughly covered in this forum (using the 'search' feature is your friend).

When new threads begin, on topics previously covered, all the added/fragmented search results just makes it much more difficult to find the needed information.

Considering all involved (e.g. purchasing all the required materials/parts, have access to a lift etc.), this is service best left to a dealer and/or independent mechanic.

There is also an electrical connector, a.k.a. as the pilot bushing, the old design has a high frequency of leaking and it would cost little more to replace with the new design, during the oil service.

All considered, this was a service I choose to have the dealer perform for $325 (including the pilot bushing).

etownbala

Found a good *pdf with step by step instructions on the oil change. Only thing is doesn't show is how to get the rest of the oil out of the Torque Converter.



KRis

MarcusF

I hate to be the bearer of bad news, but the converter drain plug was discontinued before your model year. You can't get the fluid out of the converter without dropping the trans.

The seal that Serndipity is referring to costs less than $5, so you may want to install the upgraded part.

Lastly, that PDF repeatedly refers to heating up the fluid, then it talks about checking the fluid temperature before topping it off. That's because the fluid expands when it gets hot. Hot fluid reads higher on the dipstick than cold fluid. Thats important because the WIS says if the trans is overfilled, damage will occur. You may want to use a pyrometer to check the fluid temperature.

Serndipity

Attached is a .pdf regarding installing the redesigned pilot bushing.

Normally, the entire connector is changed - not just the O ring. However, it is awkward to reach, unless the car is raised on a lift.

It is not expensive (e.g. dealer supplied part was $31.50 and was same part number as that in the .pdf).

ShouldveHadaV8

How many liters of trans fluid does it take to do an trans oil change an a clk430?

ShouldveHadaV8

How many liters of trans fluid does it take to do a trans oil change an a clk430?

dlbehrns

your owners manual will give the capacity of the transm.

Chadzu

If you just drop the pan and change the filter and refill you will only get 3-3.5 liters out of the system. The total amount is much more than that, but without doing a flush its hard to get all of the old fluid out.

etownbala

I'm thinking that if you do the transmission oil change along with oil changes for 3-4 events you could theoretically get most of the oil out...

I've heard there is a way to drain it by disconnecting a cooling line and having a friend turn the car on and off...I thought I had a good instructional on it buried somewhere from my research days but cant seem to find it...

KRis

ShouldveHadaV8

So how would i know how much to put back in? And can i add new fluid through the dipstick hole?

Serndipity

Yes, the new fluid is added through the dipstick tube. Overfill is as bad as underfill. You'll need buy a dipstick to check for the proper level, at operating temperature.

Hitman0187

Can you guys actually see if the pilot bushing is leaking while under the car? or is it something that leaks on the inside of the trans?

Serndipity

Yes you can.

If left unattended, the ill effects are not only loss of transmission fluid (e.g. no dip stick to check) but, fluid wicking up the cable and damaging sensitive electronics that are the brains of it's operation .

Mechanically, the 722.6 transmission is pretty bullet proof but, that is only a small part of the story.

After many years of reading this board regarding transmission failures (e.g. search 'limp mode'), the vast majority of issues have been electrical in nature.

Specifically:

1. Although the transmission fluid was initially marketed as life time fill/service, MB has since discovered otherwise and now recommends it be replaced every 39K miles. The issue was failure of the conductor plate module, which is located inside the transmission.

2. In addition, the transmission control is based on a micro-processor unit/assembly that can be damaged by the aforementioned cable wicking. It has been a very common problem but, fortunately a fairly inexpensive and redesigned pilot bushing has been made available, to prevent this problem.

3. Lastly, a liquid spill in the sifter area, usually causes a control module located underneath, to fail.

The required labor and parts to diagnose and repair any of the above failures are not inexpensive (e.g. typically approaching the entire value of a 10 - 15 year old W208, W210 etc.).

PS: I recently replaced the transmission fluid, filter and pilot bushing on my 2001 CLK Cabrio and praying that my coffee habit doesn't wind up in the shifter module..