It was a very tense shoot, because Richard Pryor, Yaphet Kotto, and Harvey Keitel argued constantly. There were fights, verbal abuse, walk-offs, and Mexican stand-offs. According to Paul Schrader, Pryor punched Keitel and hit Kotto with a chair during filming.
According to "The Back Row, Robin's Underrated Gems: Blue Collar", the film "had one of the more tumultuous shoots that a director could experience, which nearly gave writer and director Paul Schrader a nervous breakdown and caused him to quit the film business (for a while)." Richard Pryor, allegedly in a drug-fueled rage, pulled a gun on him and told him there was no way he was ever going to do more than three takes for a scene.
When the screenplay was being written, Paul Schrader went to Detroit and interviewed real-life auto workers to get more details. One worker told Schrader "We hate management, but you know who we hate more than management? Our own union. It fucks us." Schrader recounted later he'd never seen anything like that in a movie before, and it formed the basis of his script.
According to Yaphet Kotto, his only problem with Richard Pryor was that Pryor would improvise frequently, causing Kotto to lose his place.
Yaphet Kotto said he played his character as "an Italian in black skin". Kotto figured that Richard Pryor represented the "black" character, so Kotto based his performance on an Italian-American childhood friend.