Usually the sideplate needs replacing on the handle side.The one way bearing is pressed into it and most newer ABU reels they won't sell just the bearing.The one way bearing/clutch is usually what fails.You can open the reel and try and clean the bearing.They act up if they get a bunch of grease in that bearing.Call ABU with the serial number if you need parts.
http://www.abugarcia.com/support/parts