By 1983, Japan was experiencing a serious recession and toymakers were feeling the strain. In previous years, both Takara and rival toymaker Popy had supplimented their incomes by selling their toys to manufacturers in the American toy market. Mego's Micronauts (formerly Takara's Microman) and Mattel's Shogun Warriors(formerly Popy's Chogokin) had proven that it could be done with some success. Now that the Japanese market was in such bad shape, the idea of making a second exodus to the States seemed thoroughly practical. Bandai (having recently acquired Popy) began the invasion by repacking some of its later Chogokin toys as GoDaiKin. Perhaps needing a bigger piece of the profit pie, Bandai decided to manufacture this series directly, rather than selling the rights to an American manufacturer. Takara soon followed by directly manufacturing Diakron, a repackaging of several of the later Diaclone car robots. (side note: Diakron and Diaclone are the same name with different spellings. They are pronounced the same in Japanese).

Unfortunately for Bandai, it soon became apparant that their GoDaiKin series was not selling well. The American toy market had become more crowded since 1976, now including such toy series as Star Wars and Masters of the Universe, both of which were far less expensive and aided by an enormously popular movie and cartoon series, respectively. Without a firm presence in the American market, Bandai lacked the commerical presence to create a demand for their products. GoDaiKin fell flat on its feet.

Fortunately, Takara was able to escape this fate. Some time in 1983, shortly after the initial release of Diakron, Takara had agreed to end the series and sell the toy rights to Hasbro. Whether they had sought out Hasbro in order to avoid GoDaiKen's fate or Hasbro had approached them with an offer they couldn't refuse, the deal was apparently made quite quickly. Only nine Diakron toys had been released at the time of its cancellation.

Hasbro took an interest in the idea of robots being able to disguise themselves as realistic, everyday objects. For this reason, they also purchased the rights to use several molds from Takara's Microchange series, in which robots transformed into guns, cassette players, and other everyday objects. As a result, this new Hasbro series would include both transforming vehicles and transforming household objects that were twice their size. Inevitably, this unlikely combination would require some explaining.

Hasbro decided to advertise its new product by special arrangement with Marvel Comics, producing a four issue comic book limited series along with the new toys. The series was named "Transformers". While both Microchange and Diaclone had storylines in which the transforming robots were designed by people (whether Earthlings or Micromen), Marvel took a different (and perhaps easier) approach by simply explaining that these robots were from another planet and were independent life forms. This choice was both easy and ideal for a toy line that combined two very different series of transforming robots (some which had room for 1" people and others which were obviously not on the same scale), because it allowed the writers of the comic to dismiss the robots as having simply been "born" the way that they were, rather than having been designed for a specific purpose (though later on, episodes of the cartoon would explain that the Transformers had been "designed" after all). The comic book was originally tried out as a four issue limited series, but due to overwhelming success, the storyline was extended into a monthly title.

At around the same time, Bandai brought Machine Robo, a second robot toy line, to the states, this time selling the rights to Tonka instead of producing the line itself. Tonka repackaged the series as "Gobots". Whereas Transformers had experienced some advertising exposure with its comic book series, Tonka took their product to the medium where its target audience would see it most: cartoons. "Challenge of the Gobots" brought instant attention to the product line and "Gobots" became an instant success. (For what it's worth, "Challenge of the Gobots" used the same sentient race premise as the Transformers. It's not clear which series concieved of the premise first.

One month after "Challenge of the Gobots" first aired, Sunbow (a division of Marvel Comics) aired its first episode of a Transformers cartoon, designed to win the attention of young boys that were now running out and buying Gobots toys. The plan worked and Transformers finally attained solid footing in the American market, earning tremendous profits for Hasbro and great royalties for Takara. The line expanded to include more toys from Diaclone (ex. Dinobots) and Microchange (ex. Perceptor). Hasbro also obtained licenses from a few other Japanese transforming robot toy lines to produce Jetfire (formerly from the Revell Robotech/Takatoku Macross lines), Omega Supreme (from the Toybox Mechabot-1 line), Shockwave (from the Toyco Gun-Borg line), the deluxe insecticons (from the Takatoku Beetras line), the deluxe autobots (from the Takatoku Dorvak line), and Skylinx (from an unknown Toybox line). Most of the toys were then worked into episodes in the first and second season of the cartoon, though there seems to have been a licensing problem with including the Takatoku toys in the cartoon. Thus, Jetfire appears as the very different Skyfire, and the deluxe autobots and insecticons never appear at all.

By 1985, Transformers had became so successful that Takara decided to end its Diaclone and Microchange series all together, producing their own version of Transformers instead. A new relationship was initiated between Hasbro and Takara, in which the Takara toy dictated the American toy line and cartoon, which then dictated the Japanese toy line and cartoon. The Japanese cartoon and toy line continued without interruption until 2001, long outlasting the American toyline and cartoon.

Though Hasbro stopped using moulds from other toylines after 1985, it continued to use Diaclone designs until at least 1986. Ultra Magnus (previously Powered Convoy) was the last released Diaclone toy to be repackaged as a Transformer, though Metroplex was an unfinished Diaclone design. Evidence suggests that many of the Transformer toys that followed may have also been originally designed for Diaclone, including Bruticus, Menasor and Superion. There are even suggestions that Fortress Maximus may have been a Diaclone design. Takara continued to design all of America's Transformers toys prior to Beast Machines (with the exception of Action Masters). Many fans of Transformers: Generation One still argue that all of the best designs came from Diaclone.