Most of the wheels on my 1997 E420 have corroded spots, which I'm told is caused by the wheel weights. I would like to address this problem by either spot repair, or completely refinishing the wheels. If I do the latter, they will need to match factory wheels which have not been refinished. I can do these one at a time, with or without tires on the rims. Other than a little curbing, these wheels aren't bad otherwise.

I have attached pictures showing one of the wheels, with a good close-up of one of the damaged spots. The wheel is the 5 hole version used on E420's, E300D's and some E320's in the late 1990's. Original number 210-401-0402, current MB part number 6-6-47-0093-67. Hollander Interchange 65166.

I've read a lot of the posts about refinishing wheels, but I haven't seen this corrosion situation mentioned. Has anyone repaired these successfully? Does the Wurth paint match these wheels, and if so is spot painting feasible? How do the spots need to be prepared? Thanks.

Attached Thumbnails

   

Steve, the outer edge of your 1997 E420 wheels is polished so the Wurth paint is no good there. Not sure how you would restore the polished finish. I doubt that any repair/refinish would be very durable. You may want to consider buying new wheels which should be available from your local MB dealer, but they will be quite expensive.

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Fred Hoelzle

Maybe the weights shouldn't have been put on that way. If they were the self adhesive ones that go in the inside of the wheel they wouldn't have messed up the wheels.
Sorry, that doesn't help you at all. Try a little Scotch Bright pad.

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William Weatherby

Thanks Fred,
Your answer doesn't surprise me, as the rims don't look appear to be painted. It seems to me though that there must be a way to grind them down and polish them. But I wonder if that stops the corrosion process?

I have the 5 wheels that came with the car. Four of them have this problem, and the fifth (which must have been demoted to spare tire early in its life) is nice, with the exception of a slight bend on the lip. It works fine, though. I am in the process of getting three new (or newer) wheels to use with the slightly bent one, and the corroded wheels will be used just for snow tires. But I still want them to look better than they do (and I should have time to work on it over the summer).

You could hit them with some sand paper then clear coat the bare metal.

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William Weatherby

Thanks William,

Yes, the adhesive weights may have been a better way to go. But I have those on some other wheels, and if they don't get cleaned off completely when they are removed they leave behind residue that brake dust bonds to very well.

I think what I'm going to do is get the tire off the wheel I photographed, and then pick a small trouble spot to work on. Maybe a sanding wheel or grinding stone on my Dremel might do the trick. If I mess up a small spot it probably won't matter. I am pretty sure that the metal is pitted below the original surface level of the wheel, but I don't know how deep I will have to go to get to pure alloy.

Using power tools means you can mess stuff up faster. A sanding disc on a Dremel might be better than a grinding wheel on a Dremel.
Too bad you couldn't put the whole wheel on a lathe... you could leave it attached to the car up on jackstands, put the car in drive,
For safety sake, wear gloves and eye protection.

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William Weatherby

Steve, I always have new tires mounted/balanced at our local MB dealer because they use the 2-piece MB balance weights that are coated and do not damage the wheels. Tire stores normally use the 1-piece metal weights that are more likely to cause wheel damage and don't look proper on a MB wheel. You may want to consider having your local MB dealer perform future tire work for you.

I buy tires from Tire Rack and drop off loose wheels and new tires for the dealer to mount/balance. It's less work for their tech and allows me to install the wheels and torque the lug bolts properly.

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Fred Hoelzle

I took this car to a full time wheel restoration guy, Mike at P&W BMW in Pittsburgh. He confirmed that the lip of the wheel is unpainted, though the the rest of the wheel is. He said the way he would do it is to bead blast the wheels, use filler primer and regular primer to get the surface right, put it on a "spinner" to put some lines back on the lip, and then repaint the entire wheel. This would mean that they would no longer match factory wheels. This was some time ago, but I think he said it would cost something like $125 or $150 per wheel. He also suggested that I may just want to use them as winter wheels.

I wound up scrounging three NOS (New Open Stock?) wheels on ebay, which with my one half decent original wheel, became my summer wheels. I think I paid an average of $120 each for them. They look good, other than some dings on the very edge of the lips. New wheels from the dealer would have been something like $370 each.

I then tried to improve my four old wheels before mounting snow tires on them. I found that a Dremel with grinding wheels and wire brushes did a good job of taking out big chunks of the corrosion, which left pits. I did sanding and grinding and (aircraft) stripping and got one of my worst wheels looking much better, even though I didn't get all of the stripper out of the nooks and crannies. I tired of the effort, and just got the worst of the corrosion off of the other wheels, and ground out curb rash near the lips that might have led to corrosion. I gave them a few blasts with the Wurth Clear Coat and put the snow tires on. In the spring I will smooth them out and give them a better Clear Coat, and will declare victory.

What I have is a huge improvement, but I'm not enough of a body guy to make them what they could be. But apparently nobody can make them match what they used to be, at least not cost effectively.

My analysis is that much of the corrosion was caused by curb rash as well as wheel weights, and in the future I will smooth down bad spots once a year or so, and cover them with clearcoat from a touch-up tube. I'm hoping that will keep small spots from becoming big blotches.

Your wheels are produced with the same technique as the Mille Miglia Bello wheels I just purchased. The raw wheel is first painted completely, then a lathe is used to remove paint and some aluminum from the outer lip area and finally the whole wheel is coated with a polyurethane finish.

While this gives a really nice look the outer edge can very easily be compromised by curbing, wheel weights and poorly trained / sloppy tire equipment people. Dealing with nice wheels on conventional tire changing equipment is a challenge and if the person doesn't pay enough attention they can do a lot of damage. More often though it's care after the finish has been compromised that decides how much corrosion will appear. Even if the edge of the poly gets cut it can be controlled with proper waxing and / or new poly finish overlay on the outer edge.

I recently bought a used set of Mille Miglia Bello wheels where the poly had been compromised and not fixed properly. Since they were someone's winter wheels they didn't care, and likely based on the cars they drive they don't need to care, but I'm on a budget and they were inexpensive and an upgrade from the OE 16" wheels. The Bello wheels are 17x8" ET44 with very good tires, the only problem is the outer wheel lip and really the worst is only on one. The picture at the bottom is the worst one but now I think I'll repaint all four of them.

What I did initially was to tape off the outer lip by using the ridge where the lathe started removing material inboard near the spokes and then out at the edge against the tire. (Since these were recently rebalanced I didn't want to pull the tires in order to do the repair, that could mean more damage after they're repaired and that would defeat the purpose.)

Next I applied stripper very carefully with a tooth brush to the outer exposed lip taking care not to saturate the inboard tape too much and leach through into undamaged poly over paint.

After nursing that long for about an hour, reapplying liberally every five minutes since the stripper dries out after doing it's magic I began scraping off the loosened poly finish with a plastic spoon. Metal objects tend to damage the raw aluminum even more and that should be avoided.

Now that all that's cleaned away I have a couple choices. I can attempt to sand out the corrosion completely and buff the outer lip to a mirror finish or I can sand to remove corrosion and then color sand the rest of the wheel and completely refinish eliminating the original outer lip treatment, and that choice hasn't been made yet. I do know that if I decide to recoat the complete wheel all four will need to be done and that's a pita.

Here's a pic of the worst wheel with the poly removed, the main damage to this wheel was at the lip although there are other imperfections that appear to have been from the factory. The one thing that could cause me to repaint the whole group of four is the damage done near the bolt holes on two wheels from some idiot who was chunking around with the lug bolts and an impact driver apparently, chipping paint and making a mess.

This is a general shot, I'll try to get a closeup of the lip that shows where the lathe was used to cut the outer lip treatment.

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Steve A
92 W140 OM603
97 VW Jetta TDI
90 Passat variant TDI 6 speed MT
94 Chevy K1500 6.5TD
05 E320 CDI
+ others

In this closeup you can see where the outer edge was cut away after the silver paint was applied, there's a defined edge where the lathe started removing material. When I stripped the lip I taped off the spokes using this edge as a cutoff so that I wouldn't strip away more clear than I needed to.

You can also see the extent of the corrosion in this photo

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Steve A
92 W140 OM603
97 VW Jetta TDI
90 Passat variant TDI 6 speed MT
94 Chevy K1500 6.5TD
05 E320 CDI
+ others