A differential assembly includes a retainer for a cross pin having a bore aligned with a bore formed in a differential housing. The cross pin retainer is positionable at partially-inserted and fully-inserted positions within the cross pin and differential bores. At a first rotational orientation, the cross pin retainer is positionable in its partially-inserted position to temporarily retain the cross pin within the differential housing. At a second rotational orientation, the cross pin retainer is positionable in its fully-inserted position to retain the cross pin within the differential housing. Features of the cross pin retainer cooperate with surfaces formed in the differential housing to allow the cross pin retainer to be fixedly positioned and secured within the differential housing.