1991 300TE loose wiper arm shaft

[Jim Garfield]

My wiper started to hit the rain gutters at the end of it's travel and stick.The wiper arm was loose and I can manually push/pull it in and out a few inches. I pushed it back in, but after a couple wipes it works itself out again.

I took off the plastic cover on the wiper arm to see if the allen screw that holds the arm to the round stainless shaft had come loose (I was hoping this was the problem). I found that the allen screw was tight, and the shaft itself moves in and out.

I'm guessing this means that I have to open the wiper "gearbox" to find what has become detached, but thought I would see if this is a common problem. I've only had the car three weeks, and am still getting up to speed with w124 specific problems. I did a search, and found many wiper related threads, but nothing specific about this shaft moving.

Thanks in advance for any insights.