Harmonic Balancer SLK32

[hookedon210s]

It appears that MB still doesn't have the harmonic balancer issue resolved. My wife's 2004 SLK32 with 16K mi. just ate its harmonic balancer. It started as a light chirping noise when cold (almost like an idler pulley problem). I took the car in 2 weeks ago and they changed the poly belt. The noise almost disappeared but reappeared yesterday as a louder periodic chirp after cold start. This morning it continued but I foolishly sent her to work and called the dealer to make an appointment for the earliest possible appointment. Fortunately for all involved my wife heard a loud "thunk" as she was waiting at a stop light to pull into her parking lot. She called me to tell me that the belt was squealing loudly so I told her to turn off the AC comprsessor. Once she did the squealing stopped. I decided to go look at the car in the parking lot to determine what caused the "thunk" and discovered the balancer defect. The balancer was resting against the electric fan and the belt was being driven by the smooth, steel inner "pulley" with surprisingly sufficient tension to operate all but the AC compressor. It doesn't surprise me that the balancer would fail this soon with the SLK32 since the balancer is also required to drive the supercharger. I will try to find out the part number was on my wife's original and on the replacement balancer and post it here. Mark