The wipers on my OBW have taken to slapping the bottom and top of the windshield. Wipers still work okay, but the noise is annoying. I now notice that when the wipers are turned off, that I can grap a wiper and move it up and down 3-4" before feeling resistance. Something seems wrong?? Maybe my wiper transmission gearing, or whatever, is worn to permit this extra movement. Anyone ever experience this??

 

I am thinking a replacement the wiper transmission. Is this reasonable??

May just be slipping on the splined shaft. See If you can tighten the nut a tad. 

If you move one does the other move with it?

 

There are nylon-plastic bushings on all the pivot points for the arm linkage.

If only one arm moves the bushing on the lever for that arm is broken. If both move its probably the one at the wiper transmission lever.

I just went through this on my 2001 Civic.  Same thing- wipers slapping the bottom plastic cowl below the windshield.  It was broken/super worn plastic bushings in the transmission just as Fairtax suggested.

 

I bought a used wiper transmission on ebay and that solved the problem.  Although, getting the wipers to line up correctly was a real pain as there were no marks on the transmission like some of the videos I saw online.  I spent way more time than I wanted trying to get the wiper cycle like it should be.

Thanks for all the advise. Both wipers move when pulling just one up or down on the windshield. Now that I think about it, last winter the wipers were frozen to the windshield with snow and ice. The wipers had been left on from driving earlier, so turning on the engine, turned on the wipers. However, they were frozen and couldn't move. I have to think that has caused the problem. I broke something. Now suspect broken plastic bushings, per all suggestions.