It is pretty interesting.
Both begin en media res, i.e., in the middle of the action. When The Iliad opens up, we're in the middle of the Trojan War. The Acheans, also called Argives, have been laying siege to the Trojans for a number of years but have yet to topple them. Meanwhile,Transformers open up in the middle of a war between the Decepticons and the Autobots, where the Decepticons apparently have the Autobots on the ropes.
Nestor is very similar to Kup and is probably the archetype Kup is based on. Nestor is the grizzled, aged veteran who, though legitimately wise, is constantly telling people of tales of his youthful greatness at every opportunity and continually telling the younger warriors how it is. There is something called an aristeia in the Iliad, which is essentially a moment of glory where individual warriors go on a streak of defeating one enemy after another, such that the entire momentum of the battle might be reversed. There is a clear parallel to this in Transformers, especially between Hector and Optimus Prime, both of whom reverse the tide of battle for their respective sides.
Also, prior to Hector's Aristeia, Agamemnon is going on an Aristeia of his own, wreaking havoc among the Trojans. It is not until Agamemnon leaves the field that Hector goes on the attack; likewise Optimus Prime takes the field after Devastator has been removed from the field by the Dinobots. And again like Agamemnon, Devastator takes out a Dinobot even as he is taken down himself, just as Agamemnon strikes down the Trojan who injures him and forces him to leave the field.
Megatron is upgraded by Unicron, a god, whereas Achilles is given upgraded armor by Hephaestus.
Patroclus, wearing the armor of Achilles, is struck down by Hector, who takes it for himself. Ultra Magnus, wearing the Matrix, is struck down by Galvatron, who takes it for himself.
Ultra Magnus cries out to the Matrix to light their darkest hour, whereas the character most similar to Ultra Magnus, Ajax the Greater, who, like Ultra Magnus, is a powerful, loyal soldier but not "favored" or "chosen" by the gods, has a poignant moment where, in the midst of a blinding fog, he cries out to Zeus for light, so that, if he must die, he can at least die striking back against his enemies. They're both brave, powerful warriors who do their job and actually save their respective sides from total defeat but don't receive the same level of divine favor or glory.
You have the meaningful deaths on both sides and especially, the death of Optimus Prime in Transformers, which you could parallel to the death of Patroclus in The Iliad and later on, the death of Hector. But in both Transformers and The Iliad, the deaths of individual soldiers are given weight and meaning as well.
I think there's also some similarities to the presence of the gods in both; you have Unicron and the power of the Matrix in Transformers and the Olympians in The Iliad.
It isn't that Transformers the Movie is literally the Iliad, but they are inspired a lot by the Homeric Epic structure IMO.