1989 300te...I see so many MB's with rocker panel rot...how does this happen? How does one prevent it. Mine has "surface" rust due to the peeling of the undercoating...water got underneath it.
Vehicle: 1980 w123 230 "Sport", 2005 w203 230 Sport
Location: Outside of Buffalo,NY
Posts: 1,968
RE: Why do rocker panels rot?
You answered your own question - Water.
Rockers on all cars from our MBs to a Ford Aerostar have water that gets locked in the rocker and eats it to death...
Our cars have "oneway" water drains, but water still gets in - cracks, splits, leaks, etc.. And then road dirt and junk gets in there and starts clogging it up and holding water, salt, mud, moisture, ect...
Rott - our cars are coated in a thick rubber coating, that holds all the evils to the steel and rotts it out bad like cancer.
to prevent it there are a few things...
1)early on make sure your water drains are clean
2)you can spray a oil,wax,sealer in the rockers much like the factory did (its a green color)
3)cut and weld/glue in patches (i recommend painting it, not resealing it with cheap undercoating)
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