snapshackle

I have a 2009 C350 with the offset AMG wheels. These wheels are showing visible oxidation at the hub. The car has 44000 on it. I've had it since about 100 miles. I live in Florida. MB's rep is telling the dealer that they don't warrant the wheels that have had damage from external sources. How in blue blazes can I damage the periphery of the hole in the center of the wheel where the cap fits and not the rest of the wheel? The rep left the dealership without any explanation as to how this is possible, only that they're not covering it. My contention is that they were either improperly clear coated or cast and that the oxidation has just now manifested itself.

The story improves. When MB customer service was contacted for clarification, Jen K, a rep there, parroted the exact same answer. I was looking for some logical reasoning. I thanked her for listening, she is well trained, and asked her to reduce their finding to paper and she told me she could not do that. After making a real point of telling me the conversation would be recorded from the beginning she could not write it out and sign it. What?...Why?...She contends that generally they don't see this oxidation pattern in cars with this much mileage. Generally...huh. Odd. She said they might be willing to grind and repaint the wheels. I have a decent full frame camera, a macro lens and a ringflash. I'll be posting photos.

Anyone else out there seen this? I'd appreciate a little clarity/help on this issue.

Thanks for reading this post, Snapshackle

Acapulco Bill

Posting some pictures would be helpful to all, as my W204 also with the AMG wheels (6 double spokes) resides near the beach.

snapshackle

Thanks for the reply. I don't live near the beach, but I realize photos would be helpful. I just need to go by my office and get the camera. Thanks again

Acapulco Bill

The chemical composition of the sandy soil in Florida is very aggressive. That's why only scrub pines are so prevalent in the state. It is possible that the turbulence of your rims has a "null" spot in the center, and that is why these tiny particles of contaminated sand accumulate and attack your rims.

If you do get your rims renewed, remember to hose them off every couple of days, this is a good tip for anyone living in sandy or costal geographies.

snapshackle

photos of the oxidation diminished to the blogs size limitations

Acapulco Bill

First, remove the cap and see if there is dampness or more corrosion underneath. If the cap is metallic, perhaps the difference in composition has caused an electrolytic reaction, such as between steel and copper or aluminum (a common problem in plumbing).

If you are worried about the cosmetic appearance, suggested is applying a tarnish remover, then trying to rub it out with an abrasive polish such as Brasso. If the corrosion is too hard for this, then use between No 180 to 320 grit wet oxide sandpaper with Brasso or water to gently grind this off. The apply wax to slow the return of the corrosion.

However I am agreement with you this shouldnt happen on a Mercedes Benz product. Not in less than 4 years, anyway. Try to get the MB dealer to remedy this first, my local dealer service department would. MB rims are sourced from several suppliers, and MB should be interested that these wheels, some very expensive, corrode.

I have attached a resized and sharpened image showing the worst part next to the cap. Best of luck!

snapshackle

Thank you for the input. I was stunned at the dismissive attitude I encountered from the MB rep. I agree with you that this appears to be electrolysis, which should not have occurred if the wheels were properly made. Perhaps the hub is making a bare metal to metal contact with the wheels and this is the result. This is common in a marine environment where a bronze or aluminum fitting is not carefully fastened with stainless. Seen it before. But never on wheels. Thank you again

claudiagoul

I don't live near the beach, but I realize photos would be helpful.

Acapulco Bill

@snapshackle_ Thanks and actually I have a lot of experience on a SEM (scanning electron microscope) in metallurgy, looking at alpha-gamma boundaries in brass where the nickel and copper repel each other and migrate, causing the crystalized effect on old doorknobs, etc.

This is not similar, but does show foreign oxides creeping into the metal of the rim and all your photos shows that the hub is the source point. But this may be also just contact chemical corrosion. In any case make a tempest at your MB dealer anyway.

Mawk

Ouch. Dismaying that the dealer rep will do nothing more about this than the big dodge. They won't even take a position on it? Can't be more evasive and non-commital than that.

snapshackle

thanks for the reply. Puzzling, I know. Evasive, I agree. I have a call into the sales manager and the repair manager per Acapulco Bill's suggestion, yet to hear back from them. I think the photos are clear that there is something amiss, and denial of a defect is not what I would have expected from MBUSA. Keep an I on your wheels, or from the conversation I had with Jen K at their customer service dept (CAC), any corrosion before 12000 miles rolls by.