hugocp

Need advice:
2011 R350 with 110K miles, noticed car shouldering at 30-40mph when start cold, the symptoms mostly go away after driving about 10 minutes. Never had a transmission fluid change so I brought it to do a transmission fluid change, the guy in the shop said the fluid change won't solve the problem and sent me to a transmission ship.
The transmission shop said the car needs a new torque converter and transmission rebuilt for ~$5000. After some research seems like the torque converter may be a common problem in the 722.9 transmission, but does it really need a transmission rebuilt? Or should I just do a transmission fluid change (~$400) and see if it solves the problem? Will a transmission fluid change make the situation worse? Thanks!

chassis

Shuddering at speed doesn't sound like a torque converter to me, it sounds like failing friction surfaces or hydraulic controls (valves, solenoids). Changing the fluid is the least cost option at this point, other than doing nothing. Fluid change likely won't make things worse, and it might make things better. There is uncertainty here so you need to be flexible on the outcome at each step.

Options:
1. Keep the vehicle
a. pay the money, whatever it takes, to keep it going.
b. don't pay for the repair, and drive the vehicle as long as it lasts, bearing in mind complete transmission failure may be an outcome.

2. Sell the vehicle

hugocp

Thanks for the suggestions, I brought the car to a Mercedes specialist today, they said cant find any issue using scanner nor feel the problem since the car had been driven half hour to be there. Left the car there overnight and see what they will find out tomorrow morning.

CedarMtn

The symptoms for my car before the transmission failed was a very hard 1-2 shift and 2-1 downshift when the transmission was cold. Not so much a shudder as one distinct jerk or thunk as it shifted. Only when cold for maybe the first 2 or 3 kms of driving. Dealer couldn’t find any problem. Eventually (weeks later) it went into limp mode. The first time it happened, the torque converter was replaced. When it recurred, Mercedes ended up replacing the transmission and torque converter (and many other components while it was in shop for over two week). Following that, it ran really well for a long period - but I was starting to feel the occasional hard shift (on a cold day when the engine/transmission was cold) which contributed to my recent decision to trade it in. Note: I also saw what I believe was transmission fluid dripping onto my garage floor - so fluid levels or a leak definitely could have been part of the problem.