Soon after, Megatron convinced the three original Dinobots to join him against Prime. Two new Dinobots, Swoop and Snarl, came to his aid. When Optimus, after being defeated by them, saved Grimlock's life, the Dinobot leader rejected the Decepticons. Apparently, the new Dinobots were without question accepted into the group, which has remained tightly knit ever since.
During a duel between the two faction leaders, the Ark was attacked by the Constructicons. The Dinobots, the only Autobots guarding the base, easily repelled their assault. After forming Devastator, the Constructicons were able to fight off the Dinobots, but neither team could significantly damage the other.
Some time later, Powerglide discovered an island that contained prehistoric life. Realizing that such a place would be perfect for the Dinobots to train in, Optimus gave the Dinobots permission to relocate there. The training went well, but didn't last long because the Decepticons soon arrived to collect energy. In the ensuing fight, the Dinobots were pushed by a Megatron-induced stampede into a tar pit. However, even this didn't stop them, as Slag was able to boil the tar away, allowing them to escape. This time, the Dinobots succeeded in driving off the Decepticons. However, the Autobots realized by now that Dinobot Island, as it had been dubbed, was too dangerous a place to inhabit, and asked the Dinobots to return to the Ark to live.
When both Earth factions began malfunctioning due to a Cybertonium deficiency, the Dinobots, who didn't need Cybertonium, were asked to steal some from the Decepticons. Grimlock refused, having only recently been nearly destroyed fighting the Decepticons, and instead took his Dinobots to Cybertron. There, they were overwhelmed by Shockwave's troops and only Swoop escaped being captured and sent to the Cybertonium mines. With the help of Spike and Carly, Swoop was able to rescue the Dinobots and at the same time, bring back some Cybertonium. Upon their return, the Dinobots were welcomed back into the ranks of the Autobots.
In 2005, Devastator was used as the principle assailant on Autobot City's main weapons. The Dinobots were sent by Optimus to stop the gestalt. Although Grimlock and Sludge were knocked away early and Swoop was caught by falling debris (and Snarl was nowhere in sight), they apparently did enough that Devastator was unable to do (much) more damage.
After crash-landing on Quintessa, the Dinobots rescued Kup and Hot Rod by defeating the Sharkticons (again, without Snarl). Wheelie met up with them and took them off the planet to rendevous with the other Autobots.
Grimlock accompanied Rodimus Prime on a mission to Charr spying on the Decepticons after a number of Autobots and Spike went missing. Grimlock's shouting alerted the Decepticons to their presense, and got them caught.
Grimlock later played an instrumental part in defeating Primacron's energy monster after the other Primatives were unsuccessful in battling it.
Grimlock also created the Technobots after an accident within Unicron's head gave him super-human intelligence. He later gave up that intelligence so that the Technobot gestalt Computron could possess that power.
Additions to the article submitted by Nick Peron.
Although they were nearly defeated, the Dinobots did succeed in stopping Shockwave when Snarl's tail brought down a mountainside to bury Shockwave. Unfortunately, that same rockslide also pushed the Dinobots into the tar pit behind them. They would go into energy-saving mode for the next four million years.
Slag was revived by Ratchet in 1984 for the purpose of defeating Megatron. The other Dinobots were soon reactivated as well, and hidden under a blanket of snow. When Megatron threatened to break the deal he had made with Ratchet, the Dinobots came out of hiding and attacked him. Possibly due to their long deactivation, the Dinobots were easily deafeated, forcing Ratchet to join the fight. Megatron was eventually beaten, albeit somewhat accidentally.
After they fought Megatron, they were quiet for a while. When Optimus ordered an attack that would limit the fighting to guerilla tactics only, Grimlock refused to participate and even went as far as to leave the Autobots. Grimlock eventually returned after Optimus's death in an attempt to take leadership forcibly. Instead, the Dinobots ended up fighting off Trypticon and saved all the Autobots in the process. For this and Grimlock's skills shown during the fight, they gave Grimlock the leadership. The power apparently corrupted Grimlock, whose behaviour departed radically (and violently) from his norm.
Eventually, Grimlock willingly surrendered leadership to the newly-ressurrected Optimus Prime, who kept Grimlock as a personal aide. This ended when Starscream, powered by the Underbase, deactivated the Dinobots, except for Grimlock, who was fired upon by the Decepticon Pretenders. Grimlock remained inactive until Ratchet stole Megatron's prototype Pretender suits and used them to rebuild Jazz, Bumblebee, and Grimlock. Nonetheless, Grimlock was unsuccessful in fighting Megatron, and needed Ratchet to take out Megatron for him once again.
After making a number of successful fuel raids against Decepticons on Cybertron, Grimlock and the other Earthen Autobots decided they needed to get back to Earth. Emirate Xaaron agreed and sent the Micromaster Rescue Patrol with them. Shortly after their jump to Earth using the trans-temporal portal, the Mayhem Attack Squad (Bludgeon, Octopunch, and Stranglehold) burst in and caused an imbalance in the portal that sent the Mayhem Attack Squad, the Autobot Pretenders and the Rescue Patrol to the center of Cybertron. There, the Autobots met their god Primus and were told of his origin by his keeper. The Keeper was killed by the Squad and a battle began. Although defeated, Octopunch tried to shoot Gimlock in the back but the shot bounced off him and hit Primus instead, waking him with a scream that alerted Unicron to his whereabouts. At that moment, Xaaron's men repaired the portal and completed the jump to Earth.
Gearing up for the impending battle against Unicron, Grimlock, Jazz, and Bumblebee were sent to the moon VsQs to look for the Creation Matrix. Although they got to the Matrix first, Decepticon leader Thunderwing took both the Matrix and their shuttle from them, leaving them on the high-gravity moon to shut down. The Autobots were, luckily, able to reach them before permanent shutdown.
After this, Grimlock was obsessed with two things: his inability to defeat Thunderwing and Megatron, and the loss of his Dinobots. Doing his research, Grimlock discovered news of a miracle energy source called Nucleon. Unable to get permission from Optimus, who was preoccupied with the Unicron threat, Grimlock stole the bodies of the Dinobots and went off in a stolen shuttle. At the Nucleon site, Grimlock discovered that users of Nucleon were kept alive beyond reason, and that some had become mentally unstable . It seemed that Nucleon affected no two beings the same way. Unwilling to test it on the Dinobots, Grimlock used the Nucleon on himself first, and felt strengthened by it. He immediately began to use it to cure the Dinobots.
After their reactivation, the Dinobots returned to the Ark to find it empty, except for the deactivated. Not realizing that Megatron was in one of the stasis pods, the Dinobots indiscrimanently pumped Nucleon into all of them. Reborn, the Autobots returned to Cybertron to face Unicron.
All the Dinobots survived the battle, and on his deathbed, Optimus named Grimlock as his successor, much to Prowl's dismay. Not believing for an instant that the Autobot-Decepticon alliance was going to last, Grimlock and the Dinobots looked for the Ark, which had gone down during the fight. The Nebulan Hi-Q met up with them, at which point they were beset by monsterously powerful mechivorous [Ed: That's robot-eating] creatures which had been brought out from under the surface by the battle. Unfortunately, Grimlock's body chose that moment to completely lock up, forcing the Dinobots to stand and fight. Desperate, Hi-Q saw that Grimlock was in fact not locked up due to damage, but rather due to a metamorphic process. Using his Powermaster abilities, he accelerated Grimlock's changes. The new Grimlock emerged and promptly drove off the creatures with his far more powerful body and weapon. However, his new abilities had a price: he was no longer able to transform.
Still not trusting the Decepticons, Grimlock had the Dinobots retrieve several stolen Decepticon battlecruisers from a place called the Rad Zone, as well as place a homing beacon onboard one of the Decepticon ships. As a result, when the Decepticons left the planet and sabotaged the Autobots ships, Grimlock was ready for it. The Autobots left immediately to pursue their foes.
Unfortunately, the Decepticons found the beacon, and set a trap for the Autobots on the planet Klo. When Grimlock saw Klo natives being chased by Decepticons, he and his Dinobots immediately attacked. The Decepticons then came out of hiding and began slaughtering the Autobots. Grimlock led the remnants of the Autobot army long enough for help to arrive, in the form of the recently-revived Optimus Prime, the Last Autobot, and the Neoknights. The dead Autobots were resurrected and Bludgeon's troops were driven off.
Several years later, Grimlock left the main Autobot army with a number of other Autobots (including the Dinobots) to form what was called a "firestormer" unit. He eventually discovered there was a large group of Cybertronians that was terraforming inhabited planets to resemble Cybertron. Going from planet to planet, Grimlock and his men destroyed a number of such operations before calling in Optimus's troops for help once they recognized the magnitude of the problem they were facing. Although he felt embarrassed at having to get help, Grimlock knew that Prime's aid was necessary.
Despite this, Grimlock felt he needed to show a more active leadership than Prime wanted. As a result, he led a small band of Autobots in a stolen Cybertronian shuttle in an attempt to destroy the Twilight command ship. Unfortunately, he was caught by Jhiaxus and was being brought to see the Liege Maximo when he was liberated by Optimus and his rescue force. Prime, however, saw Grimlock's leadership potential, so that instead of reprimanding him, he made Grimlock his second-in-command.
At one point, Prime became concerned that the Swarm was posing a threat that only a combined Autobot-Decepticon army could take on. When he left for Earth to speak with Megatron, Grimlock decided to disobey orders and follow with a small force. As Grimlock had anticipated, Megatron ambushed Prime, but was kept from killing him by Grimlock's timely intervention.
When the Swarm finally came to Earth, Grimlock led the Autobot contingent of the decidedly shakey Autobot-Decepticon alliance. His leadership and fighting skills were recognized even by the Decepticons, some of whom actually obeyed his orders over those of Razorclaw. Grimlock lasted long enough to use the life-saving rheanimum brought down by Megatron, and lived through the battle. Slag, unfortunately, was consumed by the Swarm while protecting Slingshot. [Ed: However, no statements were made afterwards as to the death toll of the battle, so it is unclear as to who was truly and irreparably destroyed.]