Recycling

"Though brilliant, it was hopelessly treacherous, and incapable of being recycled."

- Optimus Primal on Protoform X

Recycling is a process which wipes the personality and memories of a Transformer, returning them to a blank slate. This probably involves a return to protoform state as well, though that is not certain. The details of this process are completely unknown.

Recycling probably centers on the duality of Transformer memory. The conscious memory and mind are stored in a Transformer's Datatrax which can be modified, completely altered or even erased. A Transformer's spark retains the original memories which they may still recall on an unconscious level; as dreams, visions, a nagging familiarity or sense of loss.

Origins
While the first series of the Beast Wars television series was in production the producers proposed an episode where one of the cast (probably Rhinox) would enter an atavistic state and memories of a previous life as an Autobot would emerge. While researching possible Autobots to use, the producers learned of Starscream's Ghost and the episode evolved into Possession, a tale of one of the Predacons being possessed by the ghost original Starscream.

While an episode revolving around the reincarnation of older Transformers was never produced, the concept remained part of the series and would be mentioned in the Season 2 episode Bad Spark.