Sometimes I have a lot of trouble unlocking the driver's door on my Pug. The key goes into the lock without trouble but it wont turn, then sometimes I get a mechanical click and the door unlocks. In addition, the lock appears a bit loose. When the key is in the lock and the lock is opening, I can lock/unlock successively without trouble Any idea what might be the problem. If lubrication is recommended, is it possible to lubricate without removing the inner panel? Thanks PS. the door opener feels a little worn, but opens fine.