I noticed one day that my 1979 W116 300SD had been hit in the parking lot. The rear bumper was pushed in on the side, the rubber molding on the side had red paint on it, and my taillight lens was cracked.

I decided I would replace the damaged parts, which required dismantling the rear bumper. I have two spare rear bumpers with parts in various condition.

The W116 bumpers are made of aluminum covered with stainless steel and rubber trim. The fact that they are aluminum can be a false security because, though aluminum doesn't rust, it does corrode. I noticed on all three bumpers that there was heavy corrosion where the steel bumper mounts attach. This appears to be a spot where moisture, dirt, and salt can accumulate. The steel mounts were heavily rusted. I would recommend checking these areas! My car's bumper had the least corrosion of the three, but there was still pitting left. The first picture shows the corroded spots in one of the spare bumpers.

I used baking soda and vinegar which totally removed all corrosion and left a shiny surface. I then used semi-gloss black spray paint in these areas. The paint matches so well that I cannot tell where the original paint stops and the new paint starts! It looks like I repainted the entire bumper, even though I only did a few spots. I used Rust Doctor rust converter on the rusty steel parts. I replaced the damaged bumper mount shock absorber and used the best rubber parts of the 3 bumpers.

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Though it is not perfect, the rear bumper is in much better shape than it was! I don't have any pictures of what it looked like before.

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