Replaceable wear strip fitted into the car door sill groove to guide door panels.
Full Definition
The car door sill insert is a replaceable low-friction strip (typically nylon, UHMW-PE, or aluminium) fitted into the groove of the car door sill. The lower edge of the car door panels or the door gibs run in this groove, maintaining the door panel in alignment and preventing lateral movement. Inserts wear over time and must be replaced before the groove is damaged. Signs of wear include increased door wobble, door panel derailment, and visible sill groove wear. Replacement is a routine maintenance task requiring door panel removal.
