The windshield wiper on my 1990 E300 stopped working during a heavy rain storm about a month ago. It seemed like the blade was getting stuck on the side of the windshield because the arm was pushing up on the sides as well as in the middle which ended up burning out the motor. I replaced the motor, but the arm is still stopping. On low it goes across once and comes back but stops before going across again. I removed the wiper blade and the arm still stops even though it's not caught on anything. If I turn it to a higher speed it will start moving again, but still pushes up on the sides so if I put the blade back on it gets stuck. Occasionally on high speed it will still stop randomly. Any thoughts on what this could be? Thanks in advance for your help!

 

It sounds like the gears inside your wiper body are broken up. This will happen to all E-class wipers from that era.

You can remove the assembly and replace it with a new one from Mercedes, but they cost about $950 the last time I looked. You could also get one from a wrecking yard if you can find one.

The best solution I have found is to replace the gears with ones from a wiper assembly off of a 190E. Your gears are made of plastic while the early 190 (1984-1986) are made of bronze and last far longer.

The gears bolt right in; the tricky part is to "time" the wiper assembly before you put it back together. You can best do this by marking the position of the arms on your assembly so you can put them back in the same position as they were before you started.

Also get some teflon spray and spray the moving part of the wiper shaft; the part that holds the blade. This little piston will get stuck sometimes and that could be your whole problem.

Sam

 

The gears do seem to be the problem. Occasionally I can get them to "set" and the arm will move and retract correctly, but not for very long. Hopefully that means they're not completely shot. How do I access the gears inside the wiper assembly?