dontwakemeup

Any advice I can get on this matter is much appreciated.

Starting off in my car first thing in the morning, or after the engine has cooled off almost completely, I've encountered a strange shifting behavior. I noticed it the second day of ownership (first cold start), now I'm up to 2000 miles and am getting concerned that this isn't just new car finickyness. Here's the skinny: when shifting from 1st to 2nd at about 3100 RPMs (very moderate on cold engine) the stick feels as though, after mild pressure to slide it into gear, there is a clunk, almost a grind. Granted, I treat this car like gold and I've owned cars with mannys without incident so I know it wasn't a condition caused by mistreatment. It did have 28 miles before being purchased but, heck, what could possibly have gone wrong in 28 miles? Any other shifting configuration is completely fine and if I happen to hold off on shifting, say, up to 4100 RPM's, the shift feels more fluid. Shifting from 3rd to 2nd never feels bad. Approximately 20 minutes into a commute and it shifts better--wonderful after an hour. Strange, huh? Perhaps hydraulic fluid? I can't imagine it's a synchro. It feels as though the clutch isn't fully engaged--but only for that one gear combined with a cold-to-cool engine and shifting at lower RPM's. Anyone else encountered this? I've contacted the service department but received no concerned advice, other than they didn't think it was a problem. This can't be normal, could it?

speedfrk

Mine does the exact same thing. It is just a crappy transmission. The service rep said they have complaints from people on these and the SLK's w/6sp. It is very sensitive to how you shift it, what rpm, how fast, etc. But only on the 1st to 2nd shift. In other words, you have to change your driving style to accomodate the car. The factory rep drove mine and said it was normal, but that they would put a new 2nd gear syncro in if I wanted. If you shift yours slow, does it feel like it catches for a second from 1st to 2nd? I had an old Ferrari 308 that had to be fully warmed up for the syncros to work right. They expand from the heat, and actually work better when they are hot. That is why it is worse when it is cold. But the Ferrari was a 1975 model. You would think Mercedes could do better with modern technology!

Lynn

This is a common complaint. It should get better as the transmission breaks in.

MarkL

I've got a 2002 C240 6-spd w/ 6800 miles on it, and I've never experienced the slight grinding that you've described. In the DC area, it's been down to about 20 degrees in the winter, so I've shifted when it was pretty cold. I don't know about it being a "crappy" transmission, but it seems like it might be a synchro problem as you've noted. Are you sure there's sufficient clutch clearance when the pedal is pushed all the way down? I mean, maybe the linkage needs adjustment. We've all noted that the engagement point is pretty close to the floor w/ the M-B clutch -- maybe that's your problem...

dontwakemeup

Hey man, no kidding about the synchro. So are you saying that the service rep thought that installing a new one would eliminate this? Do you know if it is the same part or an improved version? I'd like to get it done if that was the case. I could use a complimentary wash! And an SLK loaner!

Iceman's C230

My c230 does not have this problem. Thank God. But mine won't shift into first gear without little force. It is still tough. But i have never grinded any gears on the car yet. So far so good except for the 1st gear.

speedfrk

I just turned 3300 miles on my car. I am going to give it until 5000 to see if it gets better. I picked my car up on Jan31st right off the boat. So it is not a real early car. Built sometime in dec.
Like the factory rep said, "We will put a new 2nd gear syncro in if you want, but I wouldn't want them taking my brand new car apart unless it got a lot worse" That's a quote.
My clutch problem is different from my trans problem though. Just wondering if anyone else had noticed this. Is the clutch adjustable?

Yellow_Fly_Red

Mine only does this when its really COLD outside...
like below -13F and I start my car in the mornings to go to work.
Doesn't bother me though. My other previous cars have trouble shifting into ALL the gears when its cold outside so to me, this is normal.

Davidta

On real cold days I had the same problem if I didn't run through the gears a few times before pulling out. Try running the pattern a few times, it shoudl get everything lubed up and unstuck and it shouldn't be a problem anymore, at least it isn't for me.

dontwakemeup

My car was purchased, off-the-boat, 2 months ago. Also, when I meant cold I meant a cold engine (that hasn't been running--first thing in the morning or on the way home from work), regardless of the air temperature...it's been 70 degrees here lately. The more I've been hearing about this topic it seems as though this IS normal for the transmission. I just will shift with a little higher RPM from now on. I've never grinded the gears but I could hear the clunk, more a notchy sound that I assume, too, is ok and normal in this situation. I grew up with the habit of driving a car slow and at lower RPM's until the car is warmed up. Perhaps I should quit babying my car so much. When a person falls in love you just can't help yourself. Cheers to the damn coolest car I've ever driven.

kingyellowsnake

People,
The reason why all of you have a hard time shifting your 6 speed transmissions in the cold, is because of the carbon based transmission oil/lube. Under -10C, the stuff has the consistency of thick mud. To resolve this, immediately invest in replacing the original transmission oil/lube with synthetic oil/lube from Mobil One. This will make your transmission shift like a hot knife through butter and will be better for your transmission in the long term. Please check with the dealer first, but I am sure there will be no problems with the switch. In addition, I would suggest you use Mobil One synthetic 0w30, 5w30 or 5w40 in the motor after the first 10000km as well. This will help your motor run better and last much longer under harsh conditions.
Good Luck.

dontwakemeup

Yes, I'm sure it would be a good idea to have synthetic fluid, surprised that isn't already used. The motor oil is full synthetic Mobil One from the factory. However, this shifting issue is on HOT days as well. COLD engine. (Under 75 degrees F, sorry don't know the conversion to C). I've talked to an additional service rep and was told that it is a very common complaint, "four a week". He claims it is a transmission design used to gently push people into quickly heating up the CAT by driving with higher RPMs. In other words, the catalytic convertor needs to be a certain temperature for optimum fuel efficiency, emissions .... So, this inconvenience will adjust the driver's shifting style to warm up the CAT quicker and will continue until the desired temp is achieved. Once the desired temperature is achieved the shift to 2nd is easier. I can't decide if that is a load of BS or what. Why does every other car I drive NOT do this? Thought I was OK with this but it still bugs me. I will look into new tranny fluid too, thanks. Anyone else with new news on this??