jezza211

Hi guys,
Anyone else have 7 speed failures ? Mine's in again getting new TCU / Hydraulics, E-motor / clutch again... This is the second time in 30,000ks
Typical turbine sensor fail but this time it didn't release the clutch and stalled the engine as I slowed for a corner, interesting thing was that even though it gave me a warning message to "Stop the car, Transmission Fault " it didn't write any fault code which meant the service guys were sure there was nothing wrong with it. This is the second time with this car that i've been 1000ks from home home and it craps the tranny leaving me to nurse it home and take it to service. You may have seen my last merc experience with a CLS that had the same problem twice in 15000ks. They ended up refunding me 100% for that car so lets see what they do this time.
I guess the boys in Stuttgart must be very proud now they have doubled the service life to 15000ks between failures.
I was assured by Mere management here that the issues with 7g had been sorted but now I see there is a class action against Merc USA re 7g failures and their lack of a permanent fix for the crappy Seimens TCU plate. If you haven't had your transmission die on you yet you have been lucky but believe me it will eventually. My car is S-300 bluetec hybrid so it's not like it's pushing big horsepower, how the hell do they fair in an S63?
Would like to hear if you have similar experience with this transmission
Cheers

superangrypenguin

Slight tangent since I know very little about hybrid MB sedans.

Are these 7 speed transmissions found on the W222 hybrid specific to only the W222, or are these transmissions also used in other models? I know the regular S class is the 9 speed version, but just looking to expand my knowledge on this.

teksurv

I'd be interested in learning how the 7G-Tronic in the Hybrid differs for the 7G-Tronic that initially launched with the standard W222 until recently replaced with the 9G.

ItalianJoe1

We rarely see transmission problems anymore on the 7 speed. They hybrid unit is different but mainly due to the hybrid motor unit in the front end, the mechanical parts of the transmission are very similar. There must be something causing your repeated issues, or just very bad luck. It certainly doesn't happen often, although we have almost no hybrids here in the US market.

jezza211

Ok, the main difference is there is no torque converter as it has an E-motor there instead and that has a clutch to release or connect the diesel engine, overall it's a good drivetrain.... incredible economy, I get 900 ks on a 70 liter tank on the open road and 600 - 700 ks on mixed use around town. Not having the Torque converter means a lot less heat is generated and heat is the enemy of the electronics inside the Transmission as it appears that warpage of the TCU plate is the precursor for sensor failure. As I said I have had this 4 times across 2 different brand new cars in a span of 45,000ks, I am less than impressed. I have driven the S500e PHEV here too and it has the 9g which seems to not have these issues but for the last 12 yrs Mere has used the 7g in everything they produce, C,E,S, SLK, CLS, ML, GL etc.
My failures have all been either on long trips (usually with some mountain driving ) or just after a long trip, 2 times it put me in very dangerous situations once nearly causing a head on crash, Having the car broken when you're away is at least inconvenient especially when the best they offer is to come and take your car away on a truck and leave you stranded on a mountain.

jezza211

some related reading....
https://www.carcomplaints.com/news/2...-lawsuit.shtml
Class action in USA