frostsdad

I have 2016 S550 4Matic sedan. Bought certified and noticed odd transmission behavior. The first time dealer reprogrammed using a service bulletin. Temporarily seemed to solve, took back and has fluid analyzed. Service tech uncomfortable with fluid condition and some metallic was present. Transmission was replaced under warranty. Sadly, I still feel the car doesn’t shift the way my 221 did, seems clunky in lower gears under light acceleration. Unsure if anyone else has experienced? My 221 shifted smoothly from day 1 and even with years and with 110k on the odometer. Curious as to thoughts from this group on whether this is a known difference between the two cars? If not, I’m going to have the dealer dig in a bit further on other potential issues.

note - I’ve had about 18 months and put 12k on the car, dealer serviced timely and past history shows transmission servicing performed according to schedule too.

Tom in Austin

Yeah, the transmissions on our cars are definitely less refined than everything else. Stiff/abrupt gearchanges can happen at any time. There are many, many posts on here from people who've tried to mitigate the issue with varying degrees of success. The one that seemed to have the best outcome was a long, laborious 'adaptation' procedure where a tech drove the car under varying conditions and 'taught' the transmission what it should do under each scenario. The guy who posted about it had this all done under warranty, and my question to him was ... how many labor hours if someone not under warranty wanted to have it done and had to pay for it? Never heard the answer but sounded expensive. Not only that, but apparently only a handful of techs have ever done this, so he was somewhat lucky that he found someone who could.

You'll probably hear from some of the people who've posted on this in the past and get a lot more feedback from them.

W205C43PFL

When you mentioned they programmed it using a service bulletin, was it something along the lines of this: https://mbworld.org/forums/s-class-w...ing-w222.html?

I am concerned about the metallic looking fluid as well, did the tech ever figured out where it came from before they replaced the transmission?

frostsdad

Thanks… no root cause analysis on the metallic fluid and I didn’t think to ask the question. I was led to believe it was contained to the trans, but should’ve asked. I’ll have to look up the service bulletin regarding the adaptation they tried. I do know they did adaptation work post new trans install.

I otherwise enjoy this car - but have to tell you’ve I said many times that I wish I’d just kept the prior W221 - the trans issue is that annoying. It does seem worse when the car is warming up after a cold start, but it certainly isn’t isolated to just that time.

CPO warranty still has much life to it so I intend to have it checked out again. I do believe they used a remanufactured/used trans part as per the warranty - hoping that it doesn’t have its own host of problems although it sounds like if the mechanics are fine the electronics may be an issue that is difficult to resolve, if not impossible.

W205C43PFL

I do hope it is a success this time. I am wondering if you should also try different dealerships as well especially those willing to spend time adapting it manually as mentioned previously.

Curious though, when you mention the odd transmission behaviour before they replaced it with a reman one, what exactly was this odd transmission behaviour that you experienced?