You don't need tear anyway, New tear is garbage on him, manage mana in lane using the mana gain passive on his melee W by hitting minion or scuttler, most people go ham if they see you in hammer form but you easily show who's the boss (Q>W>AA>AA>E>R>AA>W>>3AA>Q>E and they suddendly learn that the the guy with the hammer is Jayce and not a big fighter minion).
Youmuus is pretty core on him (ArPen, AS, MS, CDR), and that build doesn't hit 40%CD (probs 10%CD in runes?), the health regen is not even counted as a positive stats, the speedboost and slow of Righteous Glory is not fully used properly, after you did a ranged Q>E>W combo and then transforming (while T2 boots) is enough speed (you reach a maximum speed cap), and your melee Q already slows slows and honestly by this time you already killed any squishy, maybe you need to use melee E though.
Righteous glory is an item build to hard engage a team fight (by some champion who want to engage a 5v5 and champion with grab skills, Blitz, Tresh, Nautilus for example), and Jayce teamfight is weird, after you do ranged Q>E what?
You either attempt to dive backline, so you try to sacrifice yourself for a pick, or you defend yours with a 75% slow (I mean you also use you other skills but Rightous Glory gives you a slow).
You are better off with a Youmuus for increased splitpushing and dueling or Death Dance so you son't die to tanks and can heal during a fight by using you skillls IMHO.
I mostly go this build
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Order may vary (BC>Death Dance>Youmuus against tanks or bruiser in toplane starting with Phage)