window problem

I have an 86 300e whose front driver side window seems to have an issue. It moves up and down without any noise or problems to speak of. However, when it reaches the top of its path, it makes a nasty thumping sound I guess you might say. I checked for any foreign objects that could be up there obstructing motion and didnt find anything. The window seems to go into the slot fine and everything. My main questions are whats happening here and what do I need to do to fix the thing. Thanks in advance.

it is the window regulator causing the noise, the gear teeth are stripped at the end. you will need new window regulator to fix.
Ray
mercedessd@cox.net