1993 Camry..

When my windshield wipers are on at full speed for heavy raining and as they are moving back and forth, they hit the bottom of the windshield making a bumping noise that drives me nuts!

I loosening the screws holding the blades in place to adjust them several different times and they still hit the bottom of the windshield's stripping making the noise.

Is there something I can tighten or adjust in the wiper motor or inside the wiper housing to stop this problem??

 

Don't think there is any stop adjustment. Are the arm drive shaft bushings worn out allowing the wiper arm move about too much?

The motor and actuator arms are located under a removable louver panel. Remove the panel and check for loose actuator arm end fittings, etc.