Gladius

I have been told my C320 needs a new transmission. It was shifting roughly, when I took it to the dealer several days ago, and was told after inspection that it would need a new trans., torque converter, etc. to the tune of about $8,600. I bought the can new in 2004 and have had it serviced faithfully at the dealership. It has 103K miles. I called the Mercedes Customer Support for the midwest, and appealed for its help. Have not heard back yet. Has anyone had a similar problem and gotten any help from Mercedes on the repair? I thought these trans. were supposed to be bulletproofe. Please advise.