I don't know exactly when it came out but it had the drawing style of a 90s cartoon.
There are 2 main characters with mechs, 1 male and 1 female. They both have suits and the 2 suits can merge into a more powerful one.
I remember one episode where the girl was at school and the boy had to protect everyone from a pterodactyl-like creature, where he needed to merge with the other mech to defeat it. Eventually, the female gets her mech and they merge.
They continue to fight till the mech has to run from a second creature when the person who sent the pterodactyl tells it to aim fire at the mech’s shins. The shins eventually fail so they can't run but they turn the knees into wheels (or something I don't remember as much about this part) beat the monsters and return to base.
I remember the way they enter the mechs is they suit up in a basic suit like a pilot would wear. Then get on a circular platform that would go down a tube and halfway though they would say 2-3 words the tunnel would end in the mech then the mech would sorta launch/shoot out of a tunnel.