Hi guys. I'm pretty sensitive to everything going on with my cars. Probably because I've had so many problems with all of them I'm in a constant state of fear lol. I noticed that when I'm driving somewhat slow and the car shifts a few gears from a dead stop in what I'm thinking may be 3rd gear when I get to 1500rpm I feel a very slight jerk and the rpms drop a couple hundred . I'm not sure if it's shifting into another gear that is just a really close ratio or the converter is locking or its slightly slipping but I was just wondering if anyone has felt that. I am still looking for a warranty so right now I'm very afraid of any issues out of the normal especially the tranny. Thanks guys!

 

Well it's definitely the converter locking up. Seems like when the car has been run for more than 10 minutes or so and I am going up the hill to my house it will shift into what I believe is 3rd or 4th and then it's very slight, most people may not notice, or think it was a slight bump in the road, but around 1500RPM it locks. I can feel it, almost like its another shift but quicker than a normal shift. Is this normal?


I just had the trans serviced a couple days ago. I don't remember if I had this issue before or not, but I think I did.

I had the shop replace the fluid, filter, gasket, bolts, and so on. They also drained the converter. Once they drained it they filled about half the fluid and then connected the Star. The car had been off for about an hour and it was cold and rainy outside, when they pulled up the temp (This was with the car still not running, but with the new fluid, or half of it in and the trans buttoned back up) it read 138f, or 56c. They then started up the car and it looked like pumped in the rest. When I asked them about checking the level at such a high temperature, they told me the reason it was so hot was because it was sitting from the long drive I had made to get there, but when they started it and the new fluid went thru it the temperature dropped down to correct level. I don't know if that is true, but I can contest that they put in 8 liters, and it took almost all of it but a very small bit. It seems that is the norm for these trannys.. Could this service be an issue?

Maybe I am just being overly finicky and I probably am, but I seem to have the WORST luck with every mechanical thing I own.. I am almost positive my 722.6 did this same converter lockup feeling too, because I have had it before, but I just don't remember 100% if that was the car doing it, and my buddy still has it and now its got about 140k on it and still going strong..

Any help would be appreciated, thanks guys!

 

If you're that sensitive to the shift patterns of your 7 speed tranny, then perhaps you should trade in your S550 on a S600 with the bullet-proof ZF 5 speed. Shifts are almost imperceptible with this tranny.

 

It's not a matter of being sensitive. It doesn't bother me at all, if it's normal then I'll be happy and never think about it again. But I work hard for my money and really don't want to ruin a tranny if I don't have to. If I notice something out of the ordinary I like to check on it. I think I'm going to reset the adaptations.

 

The general consensus is that 7 and 8 speed auto transmissions do a lot more "hunting" for the optimal gear, which many drivers find annoying. Also, the 5 speed can handle a lot more torque than the 7 speed, thus why MB only offered the S600 and S65 in the 5 speed.

 

I believe that.. I had a 2014 Silverado Z71 LTZ with a 6 speed, and with 8 miles on it to 12,000 it would hunt and flare like crazy.. Pretty bad when your brand new truck's RPMS jump up in between shifting! I drove a couple other brand new Chevys with 6spd's and they all did the same exact thing!

I don't really care about that, but what is throwing me, is, it seems when the car has been driven more than 10 minutes and I am going up a hill I can feel it more pronounced, but it will shift to what I believe is 3rd or around there, and then a few seconds later I will feel a very slight "half shift" which I assume is the converter locking. If you weren't paying attention, or watching the tac you may think it was just a bump in the road, kind of like when your driving really slow and the trans shifts but it's so slow that the RPM's only move a couple hundred.. Now I "THINK" that I felt that on my 722.6, but I can't remember, it's been too many years.

Again, I am not being picky, or worrying about feeling that, I just don't want to keep driving it if there is a problem that I could make worse. If it's a software glitch, or something stupid, and it's not hurting anything then I'm happy, but my only fear is something is going wrong, and I don't want to be the fool that paid no attention and needs a tranny a year later.

 

cmpcpro,
Im with ya buddy.
I had purchased a used 2010 S550 4Matic with 39K mi.
Soon after driving a few days i noticed what felt like to me was from a standing stop i would feel the torque converter lock up part way though till first shift in C mode.
Then later on in about 3rd or 4th a "shutter" or "chug a lug" of the drive train...converter?
I brought it in for service and after 3 atempts to resolve that problem the dealer went as fas as swaping out the converter and valve body. After that it was still noticeable but very minable and i was able to live with it.....till
It started doing it more and more in the last few days.
I come from a long line of Cadillac cars and this is my first import/Benz. Like you said its a big price tag fr a substandard vehicle.
Have to run but i wanted to get this going....more later...

 

Let's be fair here....the W221 IS NOT a substandard vehicle. It is actually the pillar of the industry and a car that introduced many technologies not previously available in any other car. And its level of comfort and sophistication existed in no other vehicle when it was introduced.

 

Exactly,
I didnt mean the S550 is substandard. I mean mine needs service... Im going to keep on it till its back to its full glory. The Airmatic also has a faint whine or drone, other than those 2 concerns i love the car.

 

Thanks for the info! The only thing I notice is a slight bump or shutter like you say in the drivetrain after it shifts from 3rd.. I want to say my W220 did it too tho, so it may just be normal?

 

Hmm, I dunno, from what I have read about the S600 repairs, I would stay with the S550

 

They're all prone to the same issues, except that the 5 speed tranny is more reliable. That's why most folks, whether 550, 600, 65, or 63 owners make sure they have warranty coverage.