An adapter to allow a sideloading refuse collection body to empty a rear loading container having trunnions. The adapter has a pair of spaced apart trunnion pockets to receive opposing trunnions of the container. A pair of lock arms on the adapter can be lowered against the tops of opposing sides of the container to lock the container in the trunnion pockets and against a stabilizer which engages the front wall of the container. The adapter includes a guide plate aligned with and extending from the front wall of the container. Lift arms on the collection body are joined to opposing sides of the adapter.