thomashvn

Hey guys

I can surely use your wisdom here as i'm having a bit trouble with my gear shifting. I made a full service of my car that has about 250,000km. Among the things i changed were (All OEM parts)

• Fuel Filter
• Air Filter
• Oil Filter
• Engine Oil
• Transmission Fluid ATF
• Transmission Gasket
• Overflow Pipe etc..

Problem is that after as soon as i serviced the transmission of the car, when i a took it for a spin the transmission kicked few times when i accelerated sort of like a jolt or a slip. I think i pumped about 8 liters of ATF. I had 10 liters in my pump beforehand and now i have 2 liters left in the pump. Mind that i also emptied the torque converter completely and did the procedure where you change gears while the car is running at 45 degrees Celsius/80 Farenheit wait till the fluid comes out of the overflow pipe. Did i do something wrong? Is the ATF i pumped inadequate? The car gears were shifting normally before i did the transmission job. I used the Mercedes original ATF which was greenish blue color as i remember. The transmission makes no noise such as whine or whatsoever, only that strange jolt and it does it only sometimes mostly when i accelerate. It jolts the whole car. When i accelerate slowly it doesn't happen. Can it be possibly due to inadequate ATF or is it a worn clutch? The transmission is the 4-Matic 722,9. (7G-Tronic) w212 E220 facelift 2013 model.

Oda112

I would think both are a possibility ( fluid level and worn clutch).
The 722.9 4 matic needs 9.7 l of fluid if you've drained the TC.
Also, if the transmission fluid change interval was too long ( over 80k miles or 120k km) there's a high chance of friction material becoming latched in the fluid. Did you have excessive dirt on the magnets in the pan?
I would start with adding more fluid, see if it helps.

thomashvn

Hey thanks for your response. No i did not have any metal particles at all. It seems it does it only if i accelerate fast from 1st to 2nd gear but also sometimes if i break hard which forces the car to down shift quickly.

Oda112

Sounds more like a pressure issue. Maybe a relearn of shift points could fix that. That would be my first step once sure the fluid level is correct.

thomashvn

Yes, that must be it. I took it for a spin today again and it it is like is loosing power or fails to shift quickly into gear in time if i accelerate a bit faster than the usual and when the gear engages it jolts the car. It doesn't do it on higher speeds. I realized that i incorrectly pumped 8 liters instead of 9,7 as it is indicated by the manufacturer. That was because i had WIS, ASRA, EPC program on a ****ty laptop that suddenly decided to stop working so i carried out the whole service blindly using common sense. However it seems that common sense doesn't work with transmissions. Correct fluid levels do, so anyone who is thinking to service the transmission i suggest to use the software by Mercedes. Btw, i would appreciate if someone can provide me with the WIS operational steps in PDF format for a 722.9 transmission service as i haven't got the software available anymore and it doesn't work. I might return the favor one day in kind as i plan buying a new laptop and re-installing the software. But all the expenses of the car and some other personal obligations have taken a toll on me so its impossible to buy a new laptop right now. Thank you for taking the to answer my post and tommorow i will pump the additional 1,7 liters of fluid and let you know if it made a difference. (That's the point of the forum right? )

PS: I have no idea how to carry out shift re-learn points.

belarus27

When indy did my transmission change and trans. mount , they said they only put in 8 liters of fluid , and its been so far fine and smooth for a week. (Probably depends on how much fluid they drained )
good luck with your problem.

belarus27

As far as re learn process... isnt that just a simple reset , like u would have to hold gas pedal ...etc?

Oda112

Mine is underfilled as well, I only put 9l of fluid in and drained slightly more. The refill kit I bought only came with 9l of fluid and I've been kinda lazy and didn't add the extra needed. I did let it drain overnight, both the TC and tranny pan but I don't thing I got all 9,7 out. As long as you're 0.5 l + or - I think you should be fine, fluid level wise.
Shift point adaptation/relearn can be done with semi professional aftermarket scan tools ( I have the option on my Autel Ds808) , the best one would be the STAR diagnose though. You don't need an online account with MB for this, any C3/C4/C5 interface should work. There are instructions in the pdf I attached on how to do that for both upshift and downshift adaptations. There's also a video on youtube on how to do it with the STAR tool. ( )
I suggested this because it is the first logical step for diagnosing a gearbox issue. If it still misbehaves, then you can consider more invasive diagnostic procedures ( valve body, shift solenoids, TC clutch, etc. ) I personally don't think you'll have to go that route, in your case the culprit seems to be the fluid level since your GB was working fine before the fluid change.. I would only worry if the maintenance interval was severely overshot ( more than 80k miles without a tranny flush).
And yes, that is the point of this forum, thank you for understanding it. I'm more technically inclined and like practical advice from people who have dealt with specific problems rather than placid generalities.

thomashvn

Ok guys, take notes... The symptoms i was experiencing with the car were hard shifting during acceleration, usually when i going uphill, downhill or on turns. Today i lifted the car up on a friends hydraulic jack and noticed when i removed the underbelly protective plastic cover of the car that it had fresh ATF on it so i checked to find out were the leak was coming from and found out it was a leak from the pump. At first i thought it might have been ATF i spilled from the previous transmission job but it wasn't. I have never touched the pump my self before so i found it a bit strange but the pumps bolts that squeeze the gasket were a bit loose. My best guess is that it probably happened from vibrations. I know the bolts are not torqued too tight because of the pump housing being aluminum however the bolts weren't tight enough to squeeze the gasket tight enough so it caused the leak. I must have added two more liters of ATF today to replenish the amount that was lost from the pump leak and guess what. The car started shifting normally again and no gearbox damage, so i got lucky i guess. However the point is that the cars transmission needs to have a specific amount of ATF in order to work properly. So for those of you doing the transmission job by your selves, i suggest be a bit carefully with the ATF quantity and make sure you get it right the first time. Assuming that this was going to be an expensive repair for me not knowing what was wrong with my cars transmission, the last three days were an eye opening experience for me regarding transmissions as i was studying all the time about the 722.9 G-Tronic transmission and how it works. You might not see the consequences right away but i can assure you it does wear out the clutches internally pretty fast if the car works with inadequate ATF fluid. Oda112 thank you for your help. I truly appreciate it and hope i can return the favor one day in the forum.

Oda112

I just got back from a very interesting long drive to DC and haven' had the time to ask about your experience. I read your post though, good details there but I have one aspect of it I can't fully understand. You're talking about a pump, usually those are in the bell housing behind the input shaft divider wall. Did you take your gearbox off the car to access that pump? Or are you referring to the ATF oil cooler ? Anyway, glad to hear all is fine now. I'mtrying to add my missing liter of ATF too. Soon hopefully )