36K timing chain replacement? So your timing chain was stretched at 36K miles?
I will check my timing chain & do a how-to thread...
To answer the OP question.
Will doing your own maintenance void warranty?
It can, if something goes wrong with what you did.
if nothing goes wrong then you wouldnt need warranty.
Because Mitsu is so good at denying warranty. Kinda like the guy from "Thank you for smoking" the Spinner. (Aaron Eckhart)