These are Wheeljack's relationships.
Wheeljack and Bulkhead have a strong relationship, as both of them were Wreckers and fought alongside each other in many battles on Cybertron. Bulkhead often refers to Wheeljack by "Jackie". Both of them are more than eager to start a fight with the Decepticons or start partying. However, on Earth, Wheeljack became somewhat uncomfortable with the fact that Bulkhead had become less rowdy and more inclined to follow orders from Optimus Prime and Ultra Magnus. Yet, Wheeljack now knows why and he still considers Bulkhead as his best friend. Wheeljack and Bulkhead continue to look out for each other and fight by each other's side.
Wheeljack considers Miko as the human-equivalent of a Wrecker, due to her personality and past actions. He even bestowed to her, the honorary title of a Wrecker after she saved him by destroying Hardshell. She further proves her worth by fighting off Starscream and his Vehicons, using the Apex Armor. He now sees her as a true Wrecker.
Wheeljack is like an older brother to Miko.
Optimus and Wheeljack are often seen together. In Loose Cannons, Wheeljack doubted Optimus of not getting his hands dirty in battles. When Dreadwing captured Bulkhead, Optimus came to help Wheeljack out of the piles of rocks, which as he did Wheeljack assumed he was Bulkhead and stated riding with Optimus made Bulkhead soft. Optimus helped pull Wheeljack out of the rubble and told Wheeljack that it's fine if he would not listen to him but placing one of Optimus's Autobots in danger made Optimus assert that rule to Wheeljack. Wheeljack told Optimus that Bulkhead knew the risks of the mission as every Wrecker knew and thought Bulkhead was buried some place around the area. However, Bulkhead's signal was off some place as Ratchet informed Optimus over his comm. Optimus tagged along with Wheeljack to search for their friend. In the Jackhammer, Optimus seemed to be a bit cramped up as he drummed his hands on his knees and asked Wheeljack why he perfers to work solo. Wheeljack stated being alone isn't that complicated. When they finally found Bulkhead, Dreadwing had placed a bomb on Bulkhead. Wheeljack tried to defuse the bomb, though Optimus went off to find Dreadwing. Wheeljack proves his original theory to Bulkhead about Optimus being the first to leave, but Bulkhead states "No, not Optimus." In the end, Wheeljack finally realized that Dreadwing is the only one who can handle it, and Optimus knew it too. Optimus was able to capture Dreadwing using a crane. Dreadwing defused the bomb and blew up the dock before escaping. Back at the Autobot base, Wheeljack says it was an honor watching Optimus work and that he had the wrong idea about him. Optimus extends his hand to welcome Wheeljack to the team, which Bulkhead presuaded him that if he leaves he might come back again. Optimus and Wheeljack seem to reconcile after that and remain close friends.
After the destruction of their former base, the team were divided but were reunited with a new Autobot named Ultra Magnus. Despite Optimus not being around this time, the team divised a plan to take on the Decepticon citadel. This plan, however, ended in every Autobot being held captive. Suddenly Optimus Prime flew in with his new robust look, which resulted in everyone escaping from the collapsed citadel. Later on, Ultra Magnus and Wheeljack discovered Shockwave's lab with the Predacon clones, which Wheeljack used his grenade to destroy the place. The original Predacon, that the Decepticons used to hunt the Autobots, made an appearance in his robot mode. Enraged by the destruction of his brethren, the Predacon attacked them and was about to kill them when suddenly Optimus came in to rescue them.
In the series finale, they secured the Nemesis with the help of their human friends. As the team went back to base after restoring Cybertron, Optimus made a speech on how they will miss their human friends/family.
In Predacons Rising, Wheeljack flew Optimus in Ultra Magnus' Ship to get the AllSpark. They made little conversations in that time. When Optimus got the AllSpark, Wheeljack stated "that's why he's Prime. When Optimus sacrificed himself to restore life on Cybertron, Wheeljack sadly watched with the other Autobots as Optimus flew in the core of Cybertron. Though they were all amazed when sparks came out of the Well.
Optimus is like an older brother figure to Wheeljack.
Of the Autobots, Wheeljack and Ultra Magnus had the hardest time adapting to one another. Originally meeting during the war for Cybertron, Wheeljack left the Wreckers after Ultra Magnus was assigned as leader by Optimus Prime. They would see each other again years later on Earth when Ultra Magnus arrived to find the Autobots in hiding and bring them together again. When Ultra Magnus scheduled his assault on Darkmount, Wheeljack and Bulkhead expressed delight in preforming their actions Wrecker-style, something Ultra Magnus told him that he could not deal with on Cybertron and could still not do so at that point either.
Their past would be brought up after the two returned to the Autobot base after having searched through the ruins of the former one and Wheeljack proceeding to throw his and Bulkhead's old lobbing ball at the latter, which he failed to catch and in doing so, allowed it to hit around the room before finally landing in front of Agent Fowler's room. Ultra Magnus told him that he would not tolerate Wrecker behavior, with Wheeljack telling him that somethings never changed and Ultra Magnus reminding him that Optimus had set him as the leader of the team. While offering him the chance to walk away again, as he had done before, Wheeljack told him that he would if the Jackhammer had not been destroyed before walking off steamed.They would again butt heads when going on a mission with Bulkhead after Optimus assigned him in charge of the Wreckers. First, Ultra Magnus angrily scolded Wheeljack for the decision to have Miko Nakadai accompany him on the mission and even bickered with him over his choice to use a bomb against Predaking in a confined space. Ultra Magnus watched as Wheeljack left the Autobots angrily and soon saw him again at the Autobot base.
The two would finally come to an understanding after being led to Shockwave's laboratory where the Predacon clones were being created. This time, Ultra Magnus was all for Wheeljack's employment of a grenade in a confined space, in order to destroy the clones. They would later team up against Predaking and on the verge of defeat, both acknowledged their respect for each other. Wheeljack helped Magnus with his damaged hand. He even talked to Ratchet about letting Ultra Magnus battle with them. During the final battle, Ultra Magnus went with Bulkhead and Wheeljack to sercure the bridge. Soundwave was able to bridge them to the lower deck of the ship. In the end, they secured the bridge with help from Jack and Miko.
Wheeljack respects Ultra Magnus and will fight by his side. Magnus is like a brother figure to Wheeljack like Bulkhead is.
Arcee teamed up with Wheeljack in Plus One to retrieve Predacon bones. During their mission, Arcee reminded Wheeljack about being on a team. Wheeljack told Arcee that he doesn't like playing with others, though he did enjoyed fighting Vehicons with Arcee. While they walked in the cave, Arcee told Wheeljack that Bulkhead was his problem. Wheeljack told her that Bulkhead was getting softer than he was as a Wrecker. Arcee told him that time changed and if Wheeljack can't adapt to it, he would rust like the bones they were digging for and he shouldn't push Bulkhead away because he has a deep connection with him. After rescuing Agent Fowler and June Darby from Knock Out, Wheeljack and Arcee returned to base where Arcee helped Wheeljack make up with Bulkhead.
After a brutal fight with Predaking, Wheeljack still felt two fisted and Arcee told him that Ultra Magnus was too. In Predacons Rising, Bulkhead and Arcee helped Wheeljack out Ultra Magnus' Ship after it was destroyed by Unicron in Megatron's body.
Arcee is like a sister to Wheeljack.
Ratchet wasn't too fond of Wheeljack at first.
In Triage, Optimus paired Ratchet with Wheeljack to get an Iacon relic. Ratchet did not like it, but he had no choice. When Ratchet arrived near Wheeljack, Wheeljack stated he will be one his best behavior and refers to Ratchet as "sunshine". While they were flying in the Jackhammer, Ratchet and Wheeljack had a little conversation. Later after Soundwave left with the relic, Ratchet helped Wheeljack after he fought Soundwave but failed to beat him and get the relic. Ratchet and Wheeljack drove back to the Jackhammer where Ratchet thank Wheeljack for backing him up. Wheeljack said goodbye to Ratchet and called Ratchet by his name instead of calling him Doc.
In Hurt, when Bulkhead was severely damaged, Wheeljack told Ratchet he watched Ratchet work and that he's a maestro at healing bots. Although Wheeljack and Ratchet are seen to have more respect for each other later in the series, in New Recruit, Ratchet angrily tells Arcee that after "the revenge stunt he pulled with Miko", he hopes not to see Wheeljack again.
In Persuasion, Wheeljack helped out Team Prime with finding a way to rescue Ratchet from the Decepticons.
Bumblebee and Wheeljack rarely interact. Despite this, they remain good friends and they act like brothers in their team.
In Predacons Rising, Bumblebee attempted to contact Wheeljack and Optimus Prime but Bumblbeee could not receive any message from them.
Smokescreen and Wheeljack are good friends. In their team, they act like brothers.
Wheeljack seems to work well with Rafael and Raf is one of his human friends.
Wheeljack never faced against Megatron physically, but he does dislike that fact Megatron nearly destroyed Cybertron. In Hurt, Wheeljack contacted Megatron from his ship to warn him about Hardshell lying about Bulkhead being offline and gave him coordinates for Hardshell to face him, to which Wheeljack would of blew up more of Megatron's energon mines if he did not comply. Wheeljack also blew up one energon mine to show Megatron how tons of energon would sound like after being exploded.
While Wheeljack did face Dreadwing on his return to Earth, he was later offered a proposal by Dreadwing to square off against him. It resulted in Wheeljack chasing Dreadwing through a trap that Dreadwing had placed. Wheeljack was left in a pile of rocks while Dreadwing took Bulkhead as bait for Wheeljack and Optimus to follow. Eventually, Wheeljack was convinced by Bulkhead that Dreadwing was the only one to defuse the bomb, and pointed out that Optimus knew too. Wheeljack may have forgiven Dreadwing, since Dreadwing gave the Autobots the Forge of Solus Prime, which Wheeljack was not there to witness but could have been informed by the other Autobots.
Wheeljack faced Soundwave in a relic hunt with Ratchet. Wheeljack fought Soundwave head on and ended up being defeated by the latter. Soundwave came close to terminating Wheeljack with the resonance blaster until Soundwave picked up on Laserbeak's signal.
Shockwave attempted to use the cortical physic patch on Wheeljack but it failed to give any information on the whereabouts of the other Autobots. Wheeljack was blasted along with Bulkhead by Shockwave in attempt to attack Darkmount. When the sudden appearance of Optimus Prime came, Wheeljack fought Shockwave and escaped with the Autobots as Darkmount came down.