Scott Eastwood Says Brad Pitt Broke Up Shia LaBeouf Confrontation on 'Fury' Movie Set

Scott Eastwood says he was ready to whoop Shia LaBeouf's ass on the set of "Fury" ... until Brad Pitt jumped in and broke it up.

Scott revisited the tense encounter on Monday's episode of "Armchair Expert with Dax Shepard" ... saying Shia's extreme method acting had already convinced him to keep his distance.

According to Scott, Shia pulled out a tooth and cut his own face while preparing for the 2014 war movie ... leaving Clint Eastwood's son thinking, "This guy's crazy."

Things finally boiled over when Scott spit tobacco juice on the movie's tank -- something his character was specifically instructed to do in the script -- and Shia took exception.

Scott says Shia fired off an "F*** you" ... prompting him to shoot back, "Stop pulling your s***. I'm gonna whoop your ass."

Shia allegedly got "froggy" ... until Brad stepped in and broke up the confrontation before punches were thrown.

Brad previously told British GQ he initially sided with Shia because they thought Scott was disrespecting the tank ... but once he checked the script, he realized Scott was merely doing his job.