Kiefer Sutherland was arrested for allegedly threatening an Uber driver who refused to pull over and let him out of the vehicle … TMZ has learned.

Law enforcement sources tell TMZ … Kiefer told police he was having dinner with a friend Sunday night. Late in the evening, he called for an Uber Black, the driver arrived, Kiefer jumped in and they were on their way to Kiefer’s home.

For some reason, during the drive, Kiefer told the driver to pull over and let him out. Kiefer told cops the driver refused, and Kiefer twice more asked the driver to pull over, to no avail.

As for what dispute triggered the confrontation, it could be a language barrier. Our law enforcement sources say, when cops arrived, the Uber driver — who spoke Russian or Armenian — requested a translator. LAPD then called someone who spoke his language.

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TJ Sabula, the Ford plant worker who yelled “pedophile protector” at President Donald Trump during his visit, has the full backing of his powerful union amid a paid suspension … and they’re fighting to keep his job.

United Auto Workers Union Vice President Laura Dickerson tells TMZ … “[TJ Sabula] believes in freedom of speech, a principle we wholeheartedly embrace, and we stand with our membership in protecting their voice on the job.”

Dickerson adds … “The UAW will ensure that our member receives the full protection of all negotiated contract language safeguarding his job and his rights as a union member.”

We showed you the video first — TJ yelled out “pedophile protector” at Trump as he was walking through the factory … and it clearly got under his skin. In response, POTUS mouthed “F*** you” to TJ before flipping him off.

For his part, TJ told the Washington Post he seized his opportunity and has no remorse … but he is concerned about his job and future employment and feels he’s being “targeted for political retribution” for “embarrassing Trump in front of his friends.”