I have a bronze moen bathroom dbl handle faucet. The handle has come out of base. When I look into the handle and the base it appears that it works on a type of gear system. What do I put in there or on the handle to make it stick?

Look to see if there is a small plug over the " gear" hole. Should be a screw inside that screws into the faucet stem.

Suggest to take a picture call moen at 800-289-6636 ask for tech support send the photo to them the will help and send you any part needed with no charge to you, good luck

John

Looks like the screw that holds the handle in got loose, and as a result, handle fell off. Do as ma0641 suggests: remove small plug in the middle of the handle, careful not to loose the screw inside, set handle back on the stem, reinsert the screw through the hole in the middle - and tighten it up. That should do

Hope that helps

Milo