1989-240 wagon--my wipers make a sort of TOO loud "click-clack" noise as it reaches the bottom side of the cycle to change direction to begin the cycle again--I have checked and tightened the nuts under the plastic cap-didn't help--they were not loose anyway-the motor is quiet-wiper blades are new-it is only the drivers side wiper that makes the noise-I think it is in the mechanism down under and behind the firewall--how do I get to it? I imagine something in the wiper mechanism has either worn out or just come loose. They do work-but that too loud "click-clack" is really annoying! Cannot access it from the engine compartment-looks like a "go under the dash" project-is that too hard of a job for anyone but a mechanic? Any other suggestions appreciated-thanks.