Here is the full list of all 27 Gear Up achievements.
Destroy 20 enemies with the Grayhound (saws).
Destroy 10 enemies with the default starter cannon.
Drown in the water at least once.
Destroy at least seven different opponents in a team game mode.
Repair (1250) armor in one round of a team game mode.
Repair 30000 armor in lifetime.
Back playing after more than one week of Gear Up absence.
Destroy 1500 enemies
Win 20 deathmatch rounds.
Win 20 team deathmatch rounds.
Recieve 500 damage without being destroyed in a round.
Win 20 conquest rounds.
Win 3 conquest rounds.
Capture a conquest tower together with 3 or more teammates.
Assist in capturing at least 20 conquest towers in a single round.
Win a TDM round overwhelmingly, with a ratio of 4:1 or higher.
Killed a deserting enemy
Win a Conquest round overwhelmingly, with a ratio of 4:1 or higher.
10 kills in a row
6 kills in a row
4 kills in a row
3 kills in a row
2 kills in a row
Destroy 100 enemies
Destroy 75 enemies
Destroy 50 enemies
Destroy 25 enemies