W212 E350 4M low gear shifting not so smooth
Here is video of my dashboard recording: flat road, cruise at 50km/h, manual gear shifting between 2nd and 3rd gear. Shifting is not ideal, it feels like engine is slow to adjust rpm for new gear ratio. Rpm change is done in two steps:
- when shifting down: rpm from 1850 first raise to 2450 and then settle at 2850
- when shifting up: rpm from 2850 first drop to 2000 and then settle 1850





I look at the internet for symptoms of worn lock up clutch and could not find many. The one I found explains lock up clutch is used to mechanically connect engine with gearbox on higher vehicle speed thus saving energy. I have no issues on higher speed. Only in 1st and 2nd gear changes which usually occurs well below 50km/h.
I also do not recognize slippage. Transmission and mounts was my first point of attention, but this unprecise engine revving during gear changing behaviour made me suspect on something relate to engine. Does dirty valve control body could create these symptoms? I also have minor trembling on idle, assumed it is due to partially worn engine mounts, but found this guy fixing it by cleaning
Last edited by OCD_enthusiast; Apr 23, 2022 at 12:23 PM.




After all your tranny is oil operated, which the oil flow is allowed by the valves in the vale body assy.
Engine mounts surely bye bye by not even 500K KM on authobahn. Take a photo of it from side view, it is easy to see a collapsed engine mount.
Below is a collapsing engine mount. Black rubber wide flap touching the protrusion of the engine mount body right side. If good mount the gap is much wider between black rubber flap to the the protrusion of the engine mount body
I replaced engine mounts as fast as I wear out my rear tires, under 20,000KM. I am super sensitive to vibrations.
Below is my 2nd engine mounts replacement, 1st time replacement at approx 10,700KM and 5 years old. I am abusive for kickdown, WOT and high speed jump on my crappy highway where bridges joints is for rally cars hahahah
18K = 18,000KM
18K = 18,000KM
18K = 18,000KM
Try to watch this videos, perhaps it may make you understand better which part of the 722.9 7 speed tranny will wear out, so you can have a better repair direction
Dont think auto tranny has no clucthes

.
Valve Body - Conductor Plate
This one is an acceleated tranny wear by AMG owners and tuned too...
Clutch wear. 300K KM
Last edited by S-Prihadi; Apr 23, 2022 at 11:50 AM.
After all your tranny is oil operated, which the oil flow is allowed by the valves in the vale body assy.
Engine mounts surely bye bye by not even 500K KM on authobahn. Take a photo of it from side view, it is easy to see a collapsed engine mount.
...
Try to watch this videos, perhaps it may make you understand better which part of the 722.9 7 speed tranny will wear out, so you can have a better repair direction
Dont think auto tranny has no clucthes

I edited earlier comment for clarity: I meant throttle control body.
Transmission was my first suspect, specifically transmission mount. But it is OK. In first days, kickdown was far worst then now: it felt literally like someone kick your kidneys. Now its much better but not perfect. I cannot explain the reasons why it's condition has improved apparently on its own...
I'm aware that dirty solenoid valve on transmission control valve could be the cause, but according to internet when valve is the issue it only misbehave when car is just started (cold). My issues are consistent accross cold/warm engine or external temperature. It is the same when start the engine and it is the same after 200km ride.
Lot of other drivers try to fix this gers changes "jerking" with interventions on transmission and most of them reporting issud if solved is back after few days. Eventually they drop it since dealership also does noz recognize it as an issue for repair.
That is why I'm looking at other direction, I do not have money to throw away on expensive transmission repairs which will not solve the issue. If transmission is good for overhaul, that is OK, but I need a way to confirm that before dismantling whole transmission....




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Last edited by OCD_enthusiast; Apr 24, 2022 at 08:48 AM. Reason: Edited for clarity
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- On flat open road set cruise speed to 50km/h
- Using paddle shifters switch gear fron 2nd to 3rd and from 3rd to 2nd
- Observe engine rpm how it change with gear shifting: is it more precise and sharp or it's the same as in my video recording (unprecise, insecure...)?
1st and 2nd gears are used to pick up from a dead stop. Leave those gears alone at higher speeds....
They are only good up to 10Km/Hr unless you want to redline your way to blue smoke...









- When roll from standstil (engage in 1st or 2nd gear) not noticable at all!
- When barely moving cca 5km/h slowly pressing gas pedal kick is noticable when gearbox connect engine to wheels and this happend frequently when you are moving in traffic column and cannot be avoided with E or S or manual shifting as it simply has to happend
- When upshift/downshift in 3rd, 4th, 5th, 6th, 7th as gear is higher kick is even less noticable, completely dissapear after 3rd to 4th and above


