Replace tranny or just converter in a 2003 03,c240 4-matic

[NHAndy]

Wifey's wagon has a case of studders at about 1700-2000 RPMs. Indie shop says bad torque converter. With 138k on speedo should I go for a complete tranny rebuild, just repalce the converter or sell this fine auto ASAP?
What are the dangers of just replacing the converter?

[mbdoc]

MB has bulletin on 2003 W203 chassis trans issues, relating to that symptom.

Trace amounts of antifreeze from trans cooler causing that issue.

Try replacing the radiator & flushing the trans.

[NHAndy]

Thanks Doc, I'll look into it and keep the forum updated.

[NHAndy]

PO replaced radiator and changed tranny fluid at 117K., car now has 139K. Any one have a used tranny torque convertor?

[ILUVMILS]

Flush the transmission first. I've fixed a bunch of cars like yours without replacing any parts. Most were due to the coolant contamination issue but a few simply had dirty fluid which affected the performance of the TC lock-up clutch. This is what causes the droning/jolting you're experiencing. Expect to pay a dealer around $400 to do this job.

There's also a chance that the transmission ECU is to blame, but you'll need to erase the transmission adaptation data and then see if the problem goes away. If it does, the ECU is at fault.