Abstract: A retainer cap assembly for attaching a track assembly to a vehicle includes a housing and at least two latch plates disposed in the housing, pivotable about a common pivot axis, between a locked and an unlocked position. A lock bar is rotatably supported on the housing, wherein the lock bar rotates about an axis perpendicular to the pivot axis of the latch plates, so as to be selectively engaged with both of the latch plates to prevent the latch plates from rotating on the pivot axis when the latch plates are in a locked position and disengaged with both of the latch plates to allow the latch plates to rotate on the pivot axis when the latch plates are in an unlocked position.