PilotAlan

So a few days ago, I suddenly felt a vibration through the pedals when accelerating, along with a "growl" or "roar" sound under acceleration.
It basically sounded like engine noise, but louder.

I could feel that something was wrong in the drivetrain. Couldn't tell what, but something was wrong. Drove straight to the dealer and had the shop foreman drive it with me. He could immediately tell something was up.

So now, my service advisor said the gears in the transfer case "didn't look right", and MB is replacing the entire transmission/torque converter assembly.
They said the transfer case is integral with the trans, so the whole thing is getting replaced.

I don't drive crazy, maybe a 4 on a 10 scale, and most of the miles are highway.
FYI

Crippled

Great second 4matic trans failure thread this week

Crippled

Serously thinking of getting rid of my 300 I keep reading bout all thee 300 4matic trans failures with low miles

BlackjackM

My transmission valve body (?) failed after 500 miles from new. It wouldn't shift out of 2nd gear....that was an interesting ride home. Replaced under warranty (and a free service A) and no problems with it since.

kevink2

So after 16K miles, gears didn't look right. That is too soon for trans gears to go bad, and suggests the gears and related parts were not right from day 1. But with no recall, could be a low probability failure.

In another case, guy had bad valve body with 500 miles. Again not a frequent problem ?

If you have a lot of miles on the trans, it's less likely to have these "new car" type problems.

Glyn is one of the trans experts, I'll ring his line ....

Glyn M Ruck

That is a new 722.9 Plus transmission I presume running on the new Blue 236.15 fluid & yes the transfer case is now integral.

From what you explain it sounds like a torque converter failure. **** happens I'm afraid. It is not common with well maintained transmissions. Yours has not been influenced by lack of maintenance however. Just bad luck. TC bearings usually fail then take out the oil pump & seals.

Let me find a clip for you. Then we can see if we are on the same wavelength.

Glyn M Ruck

Did it sound like this?

http://api.viglink.com/api/click?for...13516356912701

RLE

Pretty hard for the service writer to say "Oh, they all do that."

Crippled

i thought the 2011 was not the 7g plus? i thought only 12's and up were?!

still none the less iam scared and upset a highend car does not have this ironed out. looking to go back to an american car now

Glyn M Ruck

722.9 Plus was fitted from August 2010 build to all RWD. I don't know the launch date in the 4Matic or if they were concurrent.

Let's see if this was TC failure first.

Remember that forums concentrate failures. Some people only really post when they have trouble.

Crippled

is the transfer case seperate on the 722.9 or all in one with the trans? is it the same on the 722.9 plus?

Glyn M Ruck

5 speed 4Matics have their transfer cases separate. 7 speed 4Matics have their transfer case integral. This includes the 722.9 Plus.

Crippled

i wonder why they replace them rather than rebuild? it seems alot of people have issues with transfer casses and trans.......this is tough to swallow. i will start my new car search soon.

PilotAlan

No, it didn't. It's hard to describe. It sounded like engine noise, only louder.
The closest thing I can compare it to would be a small intake manifold leak, where it sounds like an engine - but louder.

Also, I could feel a mechanical vibration on the pedals (the seat is too insulated to feel it it your butt). The closest I could describe that would be a motor mount allowing vibration through.
I could also feel something not right in the driveline, sort of what a 4x4 feels like when you forget to take it out of 4wd on pavement.
FWIW, the shop superintendent said that the cost of having a guy rebuild it at shop rate was not worth it. Better to just drop a new one in.

I don't know what the relative costs are, but I could believe the unit cost of a mass produced tranny is cheaper than the cost of rebuild parts and man hours plus the secondary cost of a higher failure rate (with associated re-repair costs).

I'll never be able to give you an answer, I just traded it in (in the shop waiting for parts) on a 2013 GLK.

Glyn M Ruck

Enjoy the GLK. Pity. I would like to have understood what failed.

Crippled

im not far away from trading in mine too i read too many issues with these cars lately. pretty sad too cause ppl say there the most reliable mercs

herschel

Yeah I would not sell a car just because some people posted in a forum about problems. Most sources rate the C-class as very reliable, Consumer Reports labeled the W204 as 'Above Average' reliability with most weak points not related to the drivetrain.

RLE

This is your first car?

By trading in a 2011 you will lose far more in depreciation that several transmissions would cost.

Not to mention that your car will be under warranty for some time yet.

What we need here is ten posts reporting zero transmission problems so as to cancel out two or three reports of trouble.

At five years last week, my trans has no problems.

Crippled

not my first car, but also just got rid of a truck due to horror stories of gernaded transmissions. Do not want to go throughthis again. I believe most of these issues are related to the 4matic and in most cases it sounds like a transfer case issue. the t-case is one piece with the trans. still do not know what i will do yet, more than likely keep it till the warranty is out. but i do put alot of miles on my car, 15-25k in a given year (60+) mile round trip to work 5 days a week plus recreational driving on weekends adds up fast, ill blow through my CPO warranty (100k) in no time fast. i actually went by a few dealers for grins and one dealer without even wheeling and dealing offered me 27k for my car, i bought it for 28,900. i can deal with a loss like that for driving the car for 7 months and putting 11k miles on it.