There is a popping noise coming from the forward floor of the passenger side of my "82 240D. What is the "rod" that mounts just beneath the big spring behind the wheel and also mounts to the forward floor on the passenger side. There is a bolt "backing out" of the end of this "rod". While driving I hear a flapping sound from this side. Can any of you nice folks give me some pointers on this?

Thanks,
Oilslick