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Hey guys, so my car has been acting a little funky lately. It does not seem to like traffic (stop and go) whatsoever. It bump shifts itself into 3>4. I went along and reset the throttle memory and it was good, but now it is not bump shifting, but rather hesitating to shift into 3>4. I can feel it shift, hold itself for a split second, then go into gear. It is quick, but I know it is not normal as all the other gears snap right in. Along with that, I notice that at very low speeds, the engine is used to slow down the car and if I press the accelerator, it picks up hard.
Any ideas on what can be going on? I reset the throttle memory again this morning and I'm going to give her a thorough drive later to see if that helps again.
I'm going to be doing a transmission service at my MB dealer next week, which I hope will also be helpful.
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
When last did that transmission have a fluid & filter change? What mileage? Get the dealer to do a glycol test. Your car might have a leaking Valeo radiator.
101K, about to hit 102K miles. I don't think there has ever been a transmission service done, although the previous owner did do all the required services. I have about a 10" stack of receipts for it all. I'm not sure if any of those services included the trans?
First step is to either change the fluid yourself or have a shop do it. You also want the electrical connector changed out as they are a known issue on your car unless it has been replaced before. Doing those things will also help to ensure the fluid level is correct as the 722.6 is very sensitive to fluid levels. If you decide to DIY it is actually really easy and inexpensive. You find your local shell oil distributor and get a case (12 Quarts) of Shell 134 ATF which is MB approved and used by most of us here in the USA as I is so much cheaper. The case should run you under $70 if not check other suppliers I just paid like $65 or 55 cant remember. Honestly the hardest part about the whole job is getting the car up enough to work underneath safely while keeping the car level. Also setting the level perfect is a pain too but with an IR thermometer it is not to bad.
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
The TCU is under the passenger side kick plate under the carpet. Just check the fluid has not wicked up the harness from the electrohydraulic bush. If all is dry you are OK.
The TCU is under the passenger side kick plate under the carpet. Just check the fluid has not wicked up the harness from the electrohydraulic bush. If all is dry you are OK.
Service that transmission.
How does one get into the TCU as far as separating the carpet is concerned. My transmission is downshifting pretty hard again and I don't want to go hunting for expensive repairs that may not resolve anything.
I went yesterday to do my fluid and filter, but they said a bolt couldn't be removed and if they tried and it broke, I would have to pay 3 hours worth of labor @ $140/hr to have them fix it. I obviously declined, because the $500 to do the filter and fluid was already more than I wanted to spend, but was willing to bite the bullet on.
Needless to say I am close to selling the car and having someone else deal with it. For the very little time I have enjoyed the car, I've spent double that stressing this issue.
Edit: One last thing I forgot to mention, it runs good for a bit after I reset the transmission. I'm not sure if that can point me in a better direction.
Last edited by neurodave; Aug 5, 2014 at 10:24 AM.
I took it all apart, and after about 30-40 mins of trying to figure my way around, I realized how easy it all really was. I think if I had to do it a second time, I'd be in there within 5-10 minutes.
That aside, I disconnected the 2 connectors and realized there was some fluid near the end of the colored wiring leading into the black connector. The TCU itself was bone dry and didn't look to have any kind of damage. I forgot to bring a brush, so all I could do was wipe it off and check around for any other damage. I did notice that the wires were zip tied to the metal foot plate, which leads me to believe someone else may have already been in there previously.
Either way, is there a specific way to clean the connectors and take away the fluid? I'm not sure if any has gotten into the connector itself, and I was only able to wipe it up around the outside. I haven't tested the car to see if it shifts better, but tomorrow I will know.
I just want to tear it up again and make sure it's 100% clean, just not sure how.
Mop up any fluid & then use electrical or switch cleaner to clean up the plugs & wiring.
Suggest you take a careful look at the $10 electrohydraulic bush going into the transmission for leaks. If it has not been replaced the replace it.
Pleased it has not got into the TCU.
The area around the bushing was dry as a bone, there was only some light fluid at the end of the connector. I drove to work this morning and WOW, I have never felt the car shift so smooth. I was waiting my usual hesitation for 2 > 3 or 3 > 4, but the car left me waiting the whole ride to work. It just slid in like butter. I still felt a bit of a light thunk at the rear but I think this may be more of a mount issue than anything else, or at least, I hope it is. I will check back in after I've driven it a bit more, just in case this is just a one time thing and it all comes back. I plan to tear it up again later this week and give it a better cleaning with some electrical cleaner and a light brush.
Yes ~ the bush might well have been previously replaced with the new updated O Rings but they never cleaned the harness.
If we can clean it up & get the transmission to behave you might have a soft transmission mounting or flex disc issue.
I sure hope so! I was actually looking up flex disc issues a few days back. I saw a video on it being done on another Mercedes, but I recall the W203 is a bit more of a pain in the rear to do, more so in the front than in the rear. Would I be able to hold off on it for a few days? I hear that if that goes, it takes a lot with it.
Edit: For anyone who ever tackles this, the 3 bolts holding the metal plate to the car are a 10mm. The small ones holding the TCU to the plate are 5mm and to remove the side panel on the passenger kick panel is a T20 torx.
Last edited by neurodave; Aug 7, 2014 at 10:47 AM.
2012 C300 Sport 4MATIC (current) 2006 C280 Elegance 4MATIC (sold)
I just tried doing the same and got the plastic trim that covers the blower motor, the carpet and the styrofoam off but there's a nut (10mm) that keeps the kick plate in place and I couldn't get that off because it seems to be coated in some sort of rubber and when I turn the ratchet rubber shaves off. I just put everything back together and will have an indy look at it. I have a bit of a transmission quirk where if the car is in S mode and I move off first thing in the morning the transmission isn't that smooth when shifting from 2nd into first and if I do a rolling stop and go to get back on the gas the transmission clunks into 1st. If I am in C mode it's totally fine so 1st seems to be the culprit. Also, when I release the gas to slow down just a bit and get back on it the transmission sort of hard shifts into the next gear and sometimes I can hear a physical clunk from the rear. 85% of the time the transmission is very smooth though at other times it's obvious it's shifting.
I will get a fluid flush and change done on the car but could this be an electrical problem or conductor plate issue?
Does anyone know the size of the transmission pan bolts or have a lead on where I can find them? RMEuropean has the filter and gasket but the list of bolts they sell are by size, no specifics on what they are for.
Stopping by a dealership and verifying everything with the guy in the parts dept is free, you know.
Seeing as my previous experience at the dealership wasn't very good, I'd like to avoid it if at all possible. Thus why I came to the forums to see if anyone knew the bolt size.
Seeing as my previous experience at the dealership wasn't very good, I'd like to avoid it if at all possible. Thus why I came to the forums to see if anyone knew the bolt size.
Then drive up to Prestige in Paramus on Rte 17 and talk to Dave in Parts there. He's always very helpful.
Does anyone know the size of the transmission pan bolts or have a lead on where I can find them? RMEuropean has the filter and gasket but the list of bolts they sell are by size, no specifics on what they are for.
As i remember; its M6X30,
#: "140 990 46 01" or "003 990 02 12" or "002 990 53 03",,
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