This gearbox features a small snib that is turned by the cam when the key is turned. Sometimes, manufacturing tolerances mean that the snib isn't perfectly placed. If that is the case then a cylinder with a normal cam (like an Iseo or ERA) will miss the snib and won't be able to withdraw the latch bolt.
Yale cylinders have slightly bigger cams so Yale advises always to use a Yale cylinder with the G2000 lock cases. In our experience, it isn’t always the case however, the recommendation is to always use a Yale cylinder for peace of mind and no callbacks.
Operation: Lift Lever or Double Spindle
Latch reversal: Undo the screw in the latch to remove. Reverse, reinsert and replace the screw.