Trailbreaker was one of the original Autobots aboard the Ark. When it crashed, he was re-activated four million years later and his vehicle was converted to that of a Toyota Hilux. He was a hearty character who would make light of any situation (just as his tech spec portrayed him). His primary feature was his force field which he often used to defend him and his comrades.
Trailbreaker accompanied his fellow Autobots on their first mission to stop the Decepticons on Earth — a mission that took him to an off-shore oil rig. The Decepticons plundered the rig for energon and destroyed it, leaving it a flaming wreck that endangered its human crew. Trailbreaker used his force field to contain the fire, while Wheeljack used his built-in fire suppression systems to douse the flames.
Later, Trailbreaker served as a spy despite his stated function as defensive strategist. He, along with the humans Sparkplug and Spike Witwicky, camped out near the Decepticon headquarters and eavesdropped on their plans to raid the ruby mines of Burma.
As the series progressed and more new characters were introduced, Trailbreaker only appeared when his force field was needed. In "Triple Takeover" a plot by Starscream, Astrotrain and Blitzwing resulted in the flooding of a city. Trailbreaker used his force field to protect himself and a small group of Autobots from a large tidal wave.
His force field later saved all the Autobots from being disintegrated by the Sun in the episode "Megatron's Master Plan Part 2", and it again saved them from a Decepticon ambush in "The Immobilizer". Trailbreaker's last animated appearance was in episode 64, "Masquerade".
Trailbreaker did not appear in The Transformers: The Movie or the seasons beyond. However, part of the movie's storyboard depicted that he would be seen dead (much like Windcharger and Wheeljack) during the Decepticons' attack on Autobot City. This was cut from the finished movie, but it is possible that he was killed offscreen.
When civil war broke out between the Autobots and Decepticon factions, Trailbreaker joined the Autobot cause. He was command of Grimlock at the battle of Altihex, where the Autobot Overhaul was killed and Decepticon Seekers Thundercracker and Skywarp destroyed a transport full of neutral Cybertronians. Unable to save the city, the Autobots helped evacuate civilians (Transformers: The War Within #1). When Shockwave lead a force of Decepticons against the Autobot capital of Iacon, Trailbreaker was among the Autobots who defended the city (War Within #5-6).
When Decepticon leader Megatron and Autobot leader Optimus Prime disappeared in an accident with a space bridge, the Autobot and Decepticon forces splintered into smaller factions. Trailbreaker stayed with the Autobots under the leadership of Prowl. Hound, Tracks, Trailbreaker and other Autobots showed up as reinforcements when Prowl and his team of Autobots confronted Trypticon. Only Shockwave calling Trypticon away to battle the Fallen saved them. (Transformers: The War Within - The Dark Ages #4).
Trailbreaker was among the Autobots who followed Optimus Prime on his mission aboard the Ark. After leaving Cybertron, the Ark was attacked by Megatron's ship, the Nemesis. Once the Decepticons boarded the Ark, it crash-landed on Earth, where all on board were preserved in emergency stasis. In 1984, a volcanic eruption awakened the Ark's computer, Teletran-I, which repaired all on board. It reformatted Trailbreaker in the form of an Earth truck (specifically, a Toyota Hilux camper pickup).
Eventually the combined forces of the Autobots on Earth and their human allies were able to capture the Decepticons. A ship called the Ark II was built to take the Transformers and some human companions back to Cybertron, but the ship exploded shortly after takeoff. The human allies were killed, but the Cybertronians were lost in the ocean, again in stasis lock.
After Spike Witwicky used a piece of the Matrix to revive Optimus Prime, Optimus traveled to the remote shoreline where he was recovered and used the Matrix to revive Jazz, Mirage, Sideswipe, Sunstreaker, Superion, Trailbreaker and Wheeljack (Transformers: Generation One #2). Trailbreaker returned to Cybertron with Optimus Prime and most of the Autobots to face charges, after Ultra Magnus informed them the war on Cybertron had ended.
The toy that eventually became Alternators Optimus Prime was initially intended to be Trailbreaker. Takara requested that Hasbro make the truck model be Optimus Prime instead, as pick-up trucks are not popular in Japan — they believed the only way the toy would sell was if it was the popular Optimus Prime.
When the Optimus toy was redecoed black into Nemesis Prime, some fans took to transplanting the head off Swindle or Rollbar onto the black pick-up to make an Alternator Trailbreaker. Fan-made sticker sets have even been produced and sold to add details making the figure look even more like Trailbreaker.
Trailbreaker was amongst the Autobot heroes of the Great War welcomed back to Cybertron and soon transported away by Unicron. Trailbreaker was the only one not reformatted into a new body, but he was forced to fight for Unicron's amusement (so that the Spark energy from fallen combatants could revitalize Unicron's shattered frame). Trailbreaker eventually freed himself by performing a risky spark swap with Silverbolt. All were subsequently freed by the resurrected Optimus Primal,and Trailbreaker went on to serve him as part of the new Autobot faction.
Although Universe ended at issue #3, the flashback of Optimus Prime would reveal what happened. In the final battle between the forces of Optimus Primal and Unicron, the Chaos-Bringer had disappeared (due to the events of Transformers: Energon), with Primal's forces barely making it out. Trailbreaker was among those seen escaping.
A toy called Ironhide in Transformers: Universe was painted in the colors of Generation Ones Trailbreaker. It is suspected that this toy (along with a version of Transformers: Robots in Disguises Prowl 2, repainted in G1 Red Alert's colors) was intended to be a part of an earlier line of eight Spy Changers, produced as homages to classic Generation One Autobots cars. Because those eight toys both resembled and carried the names of their Generation One counterparts, it would seem more appropriate for the Transformers: Universe version of Ironhide to have been named Trailbreaker instead.