First time posting here, hopefully it's okay I'm making this thread, I couldn't find anything on this on the boards, and didn't want to necro-post some other one on the 722.9 issue.
I have an '07 with 70,000 kms and have been having some trans issues that seem indicative of the well known conductor plate issue I've read about on here. The thing is, I have had no check engine lights come on whatsoever, and in every other post I've seen on this there seems to be codes. Could this be something else? I finally brought it into the dealership for diagnosis today as it was jerking as well as feeling stuck in a gear or limp mode (turning it off and on again has fixed it every time), but I've been getting some hard shifts too, but never an engine light. Could this still be the conductor plate issue all things point to it being?

Also, if it is the conductor plate I'm questioning repairing it myself, as money is tight enough to warrant it (despite my usual desire to leave it in the hands of those that will take care of it the best). I found Circuit Board Medics and it looks promising, I read they do some soldering to fix it, but couldn't find details on the whole process. My father works in electrical and solders with radios all day anyways, is this something someone like him could take on? Literally the most in depth thing I've done in a car is spark plugs, but I have more knowledge than what I've actually used, and been wanting to wrench around a little more, and there seems to be great tutorials online for this issue that make it look straight forward enough to manage, should I go for it myself? I read also that I should use Mercedes' own transmission fluid rather than buying it from some shop, is this true?

Sorry if these have been answered before, I'm looking for some guidance and am stressing a little that it's gonna be alot of money whatever's going on.

 

Hello, im new also (sorry, help is on its way!) but i did some searching after reading this post and ended up on this page https://www.mercedesmedic.com/must-r...nductor-plate/ Have you read that one? the symptoms sound exactly like your problem, even down to turning the engine off and on again. Theres also a teardown/inspection video in that article. Not good news it

 

Yeah I came across that one. Everything seems to point to the conductor plate issue, I'm mainly questioning because I've never had an engine light on. I guess I'll find out soon regardless, I'll update with what the dealership says, still not sure if I should try the work myself or not though if it is this issue though.

 

First mistake! Trying to fix something before making a proper diagnosis. If your repair is gong to be based on guesswork then there is no hope of being successful

 

Couldn't agree more, I think you've misunderstood, I haven't tried fixing anything yet! I've brought in, and am waiting on a proper diagnosis before starting anything, but based on early diagnosis it's pointing to this issue. Always good to have more information, even in early on in locating an issue though.

 

Don't i know it... i replaced the clutch/slave on my manual opel 5 speed... 2 months later, clutch gone again.. turns out it was a broken master clutch cylinder causing the slave to not fully disengage leading to clutch failure, horrible experience.

According to my youtube video watching and google expertise, what i would do in your situation is take a clean pump + hose (for oil changes) to suck a cup of oil out to inspect it.. color and odor (black and burned = bad) to further investigate - drain as much oil as you can with the pump, and then remove the pan carefully (still some oil left in) and inspect the dirt in the pan - black clutch dust and some shimmering silver dust = normal but brass / copper coloured = bad, r.i.p transmission. The dealership will have to do this... but then they have the car on the lift.. 1 step away from replacing your plate... so will give you a call and guilt you into paying xyz to get it fixed there and then. 70k km is not much miles at all so thats really unfortunate.

Please correct my method of diagnosing the problem if its wrong !

 

Any updates Taylor? Did you hear back from the dealership?

 

Yikes, the news is in. Quoted at $5,633.90 from the Mercedes dealership, on a car I spent $8,000 on with 70,000 kms.

$4,441.70 - Transmission Valve Body: Require to replace electro hydraulic valve body, defective speed sensors. (This would be the suspected conductor plate and the valve body in there right?)

$369.35 - Centrifuge cover: require to replace centrifuge cover due to leak.

$463.75 - Stabilizer links: require to replace RF stabilizer link, found link top rubber boot was cracked.

What should I do here, advice anyone, that's alot of money. Do you think if I took the conductor plate out brought it to them for repair, then put it back in myself to save on man hours, or just asked them for the parts to do it myself it would save much? I don't know really know what those other two are about, is that something doable by myself? Calling independent shops for quotes now...

 

Oh my,, someone has to give you some advice ' $5,633.90 ' Oh taylor . Lets look at the positives. You have a diagnosis (hopefully someone can confirm it on here what that means) but with my limited knowledge, im going to assume that the dealer isnt going to 'repair' anything , simply a new part in, and it will be this part:

722.9 Transmission valve body and tcu Control Unit Conductor Plate A 0034460310

I know nothing about the other 2 things.. are they related to the transmission? or just other parts on the vehicle

RF stabilizer link = anti roll bar drop link? (you can diy that)
centrifuge cover due to leak - sounds like an airplane phrase lol i'd need a better name to find it on google

well i found this thread , but for another model (cetrifuge cover)
https://mbworld.org/forums/c-class-w...separator.html

 

Yeah it sounds like they want to replace the entire valve body and conductor plate. Tbh if I can get this under $3,000 I would more or less be okay with that, obviously the more it is the happier I am, but $5,600 is not happening lol. Upshot, I have this entire week off, and don't work until Monday, so I have the time to do the work certainly.

Yeah the RF stabilizer is just a anti roll bar link, super confident I could do that. That would be a cheap part too.

The Centrifuge cover says this on their detailed invoice: Item Description The Centrifuge Cover or Cap is used to contain the oil in the Centrifuge (Oil Separator) and provide access to clean and check the system.

 

The centrifuge thing looks like you can DIY it. Reminds me of a brake vacuum pump thats next to the firewall. This thing has no moving parts inside it. so its just a leaking oring.. just bolted onto the back of the engine. Have a look yourself from underneath and see if you can spot the leak. Its so easy to do thats why they _only_ want you to pay $369 lol

The thread i linked above and this one cover it https://www.benzworld.org/threads/ce...1505037/page-2

You just need tools that will 'fit' : (again, have a look yourself first)

 

Where about are you located Taylor? ~$3000 is alot of money, im sure theres people on this forum who would role out the red carpet for you and help for that kind of money lol. The drop links are certainly diy, just a matter of jacking the car up and supporting it on stands safely with some nice foam floor mats for you to lay on. and the centrifuge thing is just a few bolts (in an awkward place)

The valve body thing, with my limited experience i would also attempt that myself. As long as there are instructions/videos its just 'a few bolts' - the good thing is when you remove it, you can put the pan back on (catch any drips) and bring the valve body/conductor inside to swap over stuff... and then 'reverse order' with correct torque, not much at all , 8-9nm i believe