Episode 18 of the Power Rangers Super Megaforce "Emperor Mavro" has unaccredited Steven Skyler (the Samurai Gold Ranger) & Erika Fong (the Samurai Pink Ranger) as the two singing "Rebel Rockers" at end of episode.
Many ranger actors were contacted about returning to the show for the season finale. However, most of the invitations were rescinded. In addition, the invitations were only sent out a month prior to filming.
When Troy gives Orion three ranger keys to power the Q-Rex Megazord, those three rangers are Green Ranger from Mighty Morphing Power Rangers, Quantum Ranger from Time Force and White Drago Ranger from Dino Thunder.