Ax competed in the World Wrestling Federation against many top wrestlers from 1983 to 1984 as Bolo Mongol. He fought against many top level opponents, including then WWF Champion Bob Backlund, then-WWF Champion Hulk Hogan, Sgt. Slaughter, and Jimmy Snuka.
In 1986, he returned to the World Wrestling Federation and became Super Machine with André the Giant as Giant Machine and Blackjack Mulligan as Big Machine. Super Machine was the primary mouthpiece of the team. The three Machines were introduced as rivals of Bobby Heenan and his massive tag team of Big John Studd and King Kong Bundy.
In January 1987, he returned to the WWF and formed the tag team Demolition with Moondog Rex, who wrestled as Smash while he wrestled as Ax. Rex was later replaced by Barry Darsow as Smash.. Though they began as heels, their unique brawling style and charisma made them so popular that they became faces in November 1988. They won the WWF Tag Team Championship three times as a team of two, but lost the belts at SummerSlam 1990 after they reverted to being heels by forming a threesome with Crush. Ax retired soon thereafter.