gunnerz101

Hey Guys,

I have a 14 E550, in Eco mode, when the car shifts from 2nd to 3rd, you feel a rough/harsh gear change, it is not audible. Any explanation? is this normal on our cars? Any advice would be appreciated.

thanks in advance.

Oda112

No gearshift which is felt by the driver is normal (except for sport mode when you are flooring it). There are very few cases where I caught the TCM on the W212 off guard, and for most of them it was usually my unpredictable inputs which created the perceptible shifts (usually upshifts) but they were not too harsh. Your issue might be caused by a failing clutch pack, solenoid valve, clogged valve body or just old/spent gearbox oil (also, software issues could be responsible for this behavior). If the problem persists try and get it checked, if you're lucky it will be solved with an oil flush or a TCM software upgrade/reset. You car should still be under MB warranty so the easiest route is to have the dealership look at it. Good luck and keep us posted when you get it fixed!

gunnerz101

Thanks Oda, I had an oil change done a few ago, i was hoping that would have fixed it but sometimes if the gear shift still is rough. This is also normal driving, I am not flooring the pedal or pushing the car. I will take it in and see if they can diagnose what the issue it. I am hoping its something as simple as upgrading the TCM. Will keep you posted.

Oda112

My gearbox has a perceptible upshift too( I wouldn't call it rough, it's not jolting the car but it's definitely perceivable), usually from 3rd to 4th around 35 to 40 mph while accelerating smoothly for highway merging. I know mine has a valve issue (and maybe slightly worn K1 and or B2 clutch packs) which I intend to clean in the near future, but it is still not normal. As a yard stick, I drove a 2011 E550 RWD coupe and it didn't have this issue.

nc211

Is it when the car is relatively cold? Say within the first 10 minutes of driving it after its say for a while? I’ve had several cars do that, always been related to aging fluid and warming up the gear box. Fluid replacement has almost always fixed it for me.

gunnerz101

Yes, it usually happens when initially driving the car. not too much when the car is fully warm. I will try the fluid change, see if that helps.

Oda112

Didn't you say you already did that? If it was more than 20k miles ago then maybe consider replacing the fluid, otherwise you're spending money needlessly. If your car is a 2014 it should be under warranty still, I would have the dealer look at it. Keep in mind that most 7G and 7G+ trannys have perceivable shifts when cold, but the shifts shouldn't be too harsh, just enough that you can feel them. Keep us posted when you find out what the issue is.