So I opened up my manual transmission to find that plastic speed sensor pinion gear had fallen in there and was all chewed up. Also the yellow plastic ring inside the transmission that turns the speed sensor was off.
I can’t find a way to make the yellow ring permanently stay in place. It just sits on top of the gears. I’m pretty sure it will fall off again unless there is a way to permanently mount it.
Any suggestions?

This is a picture of what that black gear looked like before it was mangled.