K3nD

Hey guys I'm fairly new to this forum but I hope someone can help me out. I recently bought a 05 c55 with 60k on it. The car has been great except for sometimes the jerky tranny. It only happens when shifting from 1st to 2nd gear when it's cold. So maybe once a day early in the morning when I leave for work.. Once the car warms up it goes away. And it only occurs on "S" and "c" (not on manual). I've read this forum a few times and people with similar issues suffers from the classic glycol contamination. But if I remember correctly the c55 doesn't have any of this issue, right? So what could be causing the tranny jerky when it's cold?

Thanks!

fleishman

TCU programing for torque converter, try reset to see if it changes behavior.

K3nD

Thanks man! I was going to get to the tranny fluid flush next week anyways and il ask them to reset it while I'm in there.. But just to confirm I shouldn't worry about the glycol contamination with this one right? I mean I haven't found any similar issue on this tread concerning the c55

Viper98912

It's the tranny fluid. I noticed harshness in the 2-1 downshift when coming to a stop. Changing it out to the newer Fuchs 4134 helped smooth it out some. Plus, when the tranny is cold, it's also inherent that the fluid doesn't move as easily through the valves and clutch plates, making it feel grabby.

Also, glycol contamination normally doesn't affect C55's.

kent426

Clean you MAF first. If you haven't done a fluid change every 30K, I would do that next, last is broken tranny mount with reveals the torque converter lockup, it is a common issue depending on how hard you drive.

JonMBZ

If its hitting the rev limiter and shifting slow, then it's normal. At least that's how they shift from 1-2 I hate it myself it slows the car down in racing situations. The only fix I have heard about is changing the valve body solenoids, but i wouldn't screw with that... A few techs I work with say that rebuilding the trans has helped them, but I haven't done it yet, but I will eventually since they keep telling me to and "the trans will last forever if you do this"

K3nD

Hey guys, quick update.. Took the car to a local merc service center here for a tranny flush and OMG! The difference is night and day! All of me transmission problems went away! It feels like a brand new car! Thanks for all the help!

Viper98912

They put in new fluid....