I took my 2007 S550 to a local mechanic for a transmission oil change as it was the only maintenance that I could NOT do due to the need for the Star Diagnostics. I do all other maintenance myself. He quoted me $500 for the oil change which I thought was reasonable compared to the dealer. 4 hours later he called me to ask how to switch the AC off as he had overfilled the transmission. It was leaking water from the AC while he was running it on the lift and he didn't know how to turn it off.

I went to his shop and found it on the lift pissing oil all over the place.

I asked him how he filled it...

"Well alldata says that it needs 10.5 liters of fluid and that's what I did"

No Star Diagnostics, no thermal gun, NOTHING!
Paid him, took it home with a cloud of smoke from the oil on the exhaust.
It leaked everywhere.
Transmission is OK. Time to move on. It is what it is so now I have to fix it.

Further inspection revealed he used the same bolts on the pan and it was leaking badly from the right front of the transmission sump pan. I removed the wiring bracket to find a snapped stud underneath.
I have since temporarily replaced the bolts with regular bolts till I got my Star Diagnostic setup so I could do it myself. Star Diagnostics arrived and works great!

I have ordered the RED colored 236.14 fluid, Transmission Pan Gasket, Torque Converter Drain Plug and Washer, Drain Plug Washer Seal, Trans Drain Plug and the 6 Transmission Pan Bolts.

My question to this forum is since I will not talk to this guy anymore, I don't know what oil he used to fill it. From the mess on the floor it seems to be a clear ATF that was used not the red fluid that is on the OEM certified trans fluid list.

Does anyone feel that I would cause any damage draining the existing fluid - whatever that is and just replacing it with what I have on order? Or should I flush it with the right fluid then drain it and replace again? She has 117K miles on it and I do not want to have to fork out $$$ for a new one.

 

What a mess. You need to drain the fluid if it is not the red mb fluid. The problem is that you need to do a full drain as God knows what is in there - my guess is 5 quarts of normal atf and 3-4 quarts of whatever he put in. Full drain is a *****. You need to drain the oil pan, (4 quarts) remove the valve body (another 2-3 quarts) and then drain the torque converter (another 2-3 quarts).

 

Thanks for the reply.

I have 9 quarts on the way to replace whatever is in there. Do you think I may have to flush with a few quarts? Little pricey but I thought If I drained 4 quarts then filled it with 4 quarts of the red and went for a spin to dilute the stuff that is in there then drained it completely as you mentioned. Then replace all the fluids and paraphernalia just may make me feel a little better about it being done right. Or do you think it may be a little overkill?

 

Not need to flush. Your drive home already mixed up the oils inside.

Drop pan, disconnect tranny connector (be careful as it is fragile), observe servo shifting setup (so you can put it back together later) and remove servo. Drop valve body (kept in place by quite a few bolts, be ready- it is somewhat heavy and also more atf will drain). Next turn motor to align torque converter so you see the drain bolt (you will need a long hex wrench to reach it), drain it. While you have the valve body off remove solenoids (one at a time as they are different) and observe solenoid strainers for clogging with metal particles. If found use a small pick up magnet to remove them. Very gently- strainers are fragile. Do not blow them with compressed air. Clean solenoids will improve shifting. Keep everything very clean when working on and around the valvebody. Cleanness is essential. The valve body is like an alien spaceship and works in a similar fashion lol.

Assembly is in reverse. Make sure the new tranny filter snaps into place- I have seen many of them just laying on the pan bottom because they were not clicked in place. Do not overtorque the tranny bolts as they will snap. Have a proper low value torque wrench and follow the procedure.

Filling is done with star/ das atf temp readout. Pump in 8 quarts (you got the pan drain plug adapter, right?), start engine and let atf warm up to specified temp. Remember that depending on your pan design (new/ old) there are two different temps. Identify your pan and use correct temp. If in doubt take a pic of pan post here and I will tell you the design and corresponding temp. Remove fill hose and let excess atf drain until it starts to dribble. If nothing drains you need to add more atf. Stop engine, add another quart and let atf cool of a bit. Start the engine and let atf come to temp again. Remove and let drain until dribble. Install quickly drain plug. You are done.

 

a dealership charges 450 -500 to do the transmission service no? why did you take it to Jiffy Lube!!!

 

Guess I didn't see the part on dropping the valve body(selective reading I guess).

Sounds like a weekend job as rushing this wouldn't be good. I wanted to look at the shifting servo's at some point as they make a noise when shifting. Probably a bush of some sort somewhere in the linkage. I will confirm the pan type when I remove the underwear. Found out that there where 2 different type's in my research. I assumed it was the newer type as they corrected it in 2005 if my memory serves me right from reading here. I ordered the White type spout for inside the transmission(the one you clip out when draining all the fluid from the sump). If the pan is the old style I think I will get the new style as more fluid is always good. I will look into the pan early next week so I can have everything I need to finish it. Don't want to leave the valve body off for long. Do you know off hand what the torque settings for the valve body bolts? Pan bolts are 9 nm if I am correct. Keep you posted on my progress.

Much appreciated

 

Dealer quote was $780. It would have been a better experience at Jiffy Lube

 

Next step if this was done at a franchised shop is to contact the legal department and demand compensation for incompetent work. I would take your vehicle to a dealer and have them drain and flush your transmission and perform a complete inspection which should be paid for by the company that performed the job. If you do need receive satisfaction, file a small claims lawsuit.

 

$780 has to be a full drain. $150 for parts and 4 hours of labor. Haven't looked, but sounds about right.

 

Pulled the cap on the bell housing to see fresh tool marks on the drain plug for the torque converter so I believe it was a full.

 

The shop was the same shop that I took my S430. Under new owners. Small mom and pop shop. It was just convenient as it was a mile away. Gave them a chance...FAILED! Just motivated me to get the Star Diags so I wouldn't have another shop attached to my udder. There is other work that needed to be done with Star. All done now besides the transmission.

 

Is there a place in the forum where I can make my Star available to other local members? It's a great tool. After this mission I don't think I will be using it for a while.

 

lol. bold words...

 

Hmmm

Not a lot of space here. Actually quite perplexed as how to accomplish this without removing the transmission. Any idea's

 

ah, you have one of those. some models/ iterations/ versions have more clearance than others. if yours does not appear to have enough room to remove servo you can loosen the valve block and see how it slides out of the servo lever. normally it is not recommended as if you drop the valve block you might break the servo assembly... but in your case just look carefully how it is setup. you might have to remove the spring bracket that guides the servo lever. use common sense.

 

Took me a few to figure out it was under the pan you were refering too
Now I have another issue. When I removed the valve body I gently wiped the machined surfaces(since this is the first time I didn't know they where machined until I wiped them). Nice and shiny! They where covered in black soot. Debris from the clutch plate I am going to assume. When I tilted the valve body the ATF oil came out of the holes from the body and they are trailing the same black soot. Soot in the valve body

So my question is do I need to know anything(besides where everything goes) to strip and clean this valve body? Or is this not for the faint hearted

 

The Solenoids are coated with that soot too.

Cleaned the filters on them as you recommended. Not too dirty there but inside where the solenoid picks up fluid is BLACK just like the solenoids.

 

Good job. Some clutch material is normal. Check magnets in pan for metal shavings. Metal paste on magnets is ok, shavings you can recognize- not so much. Use atf to wash surfaces if you wish so. No solvents.

Be very careful and check and recheck the fit of the pan gasket when installing the pan. The gasket likes to move especially in the corners and get pinched. Make sure you see the tabs and use your fingers to feel the gasket sticking out a bit.

 

Thanks for all your help ALX.
Against your recommendation (Didn't see your message) I disassembled the valve body to give it a thorough cleaning and found I was missing 2 plastic check valves.



Don't have the foggiest idea how the transmission was working without them.

I am going to post a request here and timeout on this until I can find some used ones. Don't even want to think about what happens if I can't find some.

 

Got myself a used valve body on ebay. $90 with delivery 1 week.

 

How do you know you were missing them in the first place? The valve body is a multi- configuration capable and it is possible that the "missing" valves might be part of your specific configuration. I am the first to confess I never opened a valve body, but i do not believe that if something that important was missing the tranny would perform at all.

 

That's what I was thinking alx. If you are the first to tear into this tranny I doubt it ever had the check valves. Hate to see you put them in and blow something up.

 

Agreed

Little history here.

I have had this S550 for 8 months or so. I got her for a song. I have been slowly repairing little issue's here and there. New wheels, rotors, brakes, charcoal canister, misc gaskets etc. All the stuff I could do because I could see it visually and take care of it without the star diags and with the help of this forum.

Trying to stay on topic here

The transmission had a random problem with down shifting and pulling off from a complete stop. The take-off from a stop seemed to drag until I reached higher RPM. In downshifting I would approach a stop light and it would downshift into a lower gear and if the light would turn green before I stopped, when I gave it gas it would slam into the previous gear it was in before it downshifted. I compensated for this by using the paddle shifters to override the downshifts. I assumed that it needed an oil change. I drove the car 23 miles after the oil change giving me no reference to whether this corrected the issue. Which brought me to this point in the game.

The "missing check valves" has me as perturbed as you as to how this transmission could function at all. I understand that the valve body is multi-configuration capable and it could be that the check valves were not required and just left out. However, I read the diagrams on the hydraulic flow on the valve body and how the check valve AKA (pressure limiting valve) and (pressure feed valve) allow flow in one direction only or pressure regulation when hydraulic pressure is applied from the top (White side). It also allows pressure buildup from behind the check valve (black side). When missing, the fluid in that chamber would be flowing the wrong way, be of incorrect pressure or have no pressure at all. Since the 722.9 valve bodies are all designed the same hydraulically they need all the check valves installed regardless of their "electronic" configuration.





From my understanding from the diagrams the check valves are there primarily to maintain pressure between the hydraulic accumulators and the clutches to keep them primed for the fast reaction times that these transmissions have. The check valve allows fluid through once the pressure is greater on the top than what it is bottom. After actuation the check valve closes due to lower pressure on the top of the valve and the accumulators then absorb the extra pressure reducing it back to primed, ready for actuation again. Low pressure to the hydraulic accumulators and the clutches due to the check valve missing prior to actuation would result in a pulse in hydraulic pressure slamming the clutch to which it control’s (My first symptom).
Alternatively lack of a check valve can leave the hydraulic circuit open and result in low pressure in the circuit (my 2nd symptom). The holes on the steel plate between the two half’s of the valve body (which is also the surface which the check valves seal on) restrict where necessary the flow of fluids through the check valve's (present or not) to and from the main body therefore not depleting all the pressure that could result in failure. I think that whomever rebuilt this valve body before me forgot and just got very lucky that they had the critical ones installed in the right places.

I now have a better understanding of how a premiere performance vendor without touching the transmission can offer faster reaction times and acceleration with their rebuilt valve bodies, just by increasing the primed pressure at the accumulator level.

Very ingenious design these 722.9 transmissions, just wish they had given more thought into what components went into the conductor plate.

BTW I knew nothing about this valve body before I took the damned thing out. It has been an adventure but I do not want to do this again. Had valve body problems before but never addressed it myself. Again another saving from MBWorld and it's members. How much do you think this would have cost me at the dealer?

The above theory is open to scrutiny and correction by all.

 

I guess I was the second or greater. Date on the TCM is 11/08. I have an 07.



.

 

The mission is over. Finished it last night.

The valve body was an education. The scrap valve body was from an 05 W220 with a broken connector on the conductor plate. I found it to be much newer than my old one when stripping it as the plastics inside were white and mine where yellow and brittle. Solenoids were new too. TCM had a 2012 date on it.

The valve body although identical in casting, differed in the number of check *****. The center plate although identical from the press it had differences in the size of 2 of the smaller holes where the check valves went. They had steel inserts pressed into them to make them smaller. The number of check valves was the same as mine (5 small and 1 large) but the locations where different.

So now I have 2 valve bodies and one technical reference that are all different with regards to the number of check *****, check valves and were they go.
You were right alx. This is mechanically multi-configuration capable.
Looks like I purchased this one for nothing.
Well not really as I used a lot of bits and pieces from it. The manual valve was much better condition than mine so I used that too.

In the end I filled all the possible locations for the steel ***** which are pretty easy to see if you hold it above your head in the light. If you see a pin hole, plug it with a ball. Placed the check valves according to the reference (7 small and 1 big). Replaced all the o rings and torqued it back together. Stuffed it in the tranny. Filled it with oil. It's so CLEAN!

221 miles now and shifts like butter. As much as I enjoyed this because now I know what's down there, what's in it, when next it needs attention and how clean it is, I wouldn't advise my worst enemy to do it. It's painful.