- "I'm Lieutenant Bex Kolos, but everyone in Havoc calls me Gearbox. We're a tight unit--you'll like it with us."
- ―Bex Kolos
In 3643 BBY, Gearbox was the first of Havoc Squad to receive their new member, a promising sergeant newly arrived in Ord Mantell, briefing him in the basics. After their APC walker was shot down by Separatist rockeeters, he tried to repair the walker but failed, later moving on to Fort Garnik. He was sent on an unknown mission when the sergeant was sent to help out Havoc member Zora, nicknamed Wraith.
After his mission on Ord Mantell, Bex believed that the Republic was becoming too corrupt and decided to defect in joining the Empire along with Harron Tavus. He was later present at the separatists' base when Havoc Squad defected. Prior to his defection, he was the technician for Havoc Squad (later replaced by Yuun). When he joined the Empire, Gearbox started "Project B" on Alderaan to create a massive assault walker. The trooper pleaded Gearbox to end this and come back to the Republic, but Bex refused and fought against the Havoc captain. He was defeated and finally came to realize that joining the Empire was his true mistake.
- Star Wars: The Old Republic (First appearance)