My experience has been postwar transformers and new trains don't play together well. Same in reverse. Newer electronic transformers, especially the Lionel CW80, make older AC motors growl and get hot. They work fine with a DC motor and electronic reverse unit. Another problem is they don't like postwar whistle and horn relays. Many times the whistle will not work.
In the opposite, postwar transformer whistle control doesn't like modern electronic whistles and horns, and as already stated, the internal circuit breakers are too slow and meant only to protect the transformer core. TVS's or a Lionel postwar # 91 instantaneous circuit breakers highly recommended.
