Judge Sharp said Theobald borrowed the ute about 9am on April 10 last year in Dargaville for a few hours, but drove to Whangarei and told the owner he would return it the next morning.
The police summary of facts said the vehicle owner travelled to Whangarei the next day in search of his ute, and texted Theobald repeatedly.
Theobald eventually phoned the man and abused him for being in Whangarei.
The next day - April 12 - they agreed to meet at Pohe Island in Whangarei, where Theobald repeatedly assaulted the man, and made threats which suggested he had gang links, and that the ute owner would be beaten.
Theobald drove the two men to Kiwibank in Rathbone St, and told the ute owner he had legal bills and needed $10,000 withdrawn from the ute owner's account.
The ute owner feared for his safety and obeyed.
Theobald then drove off, leaving the victim to contact his wife to pick him up.
The vehicle was returned after the ute owner's family "got involved", the police summary said.
Theobald has repaid the $10,000.