This is a tip that I thought might save somebody else's bacon someday. I'm in the freezer up here in Canada, where we get lots of winter thaw/freeze cycles. On one of these occasions, on my '88 Mazda 929, the wiper arm/blade got frozen down, so when I turned on the washer, presto, instantly wiped the serrations off the die-cast arm with the steel serrations on the post/pivot.

Oh my, what to do, as there is no way I drive any car with no wiper(s), especially on the driver side. I gave this a bit of thought and it worked, very well so far:

1. Mark the position of the arm/blade, so it can be returned as removed. A piece of masking tape and a marker under the blade works good.
2. Unbolt the arm and clean the female mounting surface well (steel wool, X-Acto, whatever), where the serrations used to be.
3. Thoroughly coat the pivot post, serrations and thread, with grease.
4. Mix up some JB Weld (or equivalent) and spread it around the arm female mount hole.
5. Remount the wiper arm/blade.

I'm sure quite a few Mercedes arms are secured like this. Coincidentally, about a week later, the same thing happened to my passenger side wiper arm, but this time, there was no ice that I could see holding it down (happened going through the carwash). I did the same fix, and got same great results.
(BTW, the grease is to keep the JB Weld from bonding the arm to the pivot, in case you finally locate a replacement arm. )

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1986 560SL
2002 Toyota Camry
1993 Lexus

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