I have a Concept C LH 7.3:1
Sometimes when I make a cast, the thumb bar wants to engage on it's own, without me turning the handle. And you can hear like the drive gear and pinion grind. I ended up ordering new gears. What could be causing this?
Your thumb bar should never snap "engaged" on a cast...most likely you have the actuator spring out of place and its not seated correctly in the frame hole its designed to be in.
We would be happy to help get your reel back to how it should be.
RE:Gears....yes, its time to order new ones. If your a saltwater guy and it hasn't been maintained you may have some corrosion on the aluminum drive gear. OR its a ball bearing and it just feels like gears. Impossible for me to know for sure without the reel in hand.