Here is a list of the quests you need to do to unlock this quest assuming you haven't done any in Azshara:

You need to do all the quests at Orgrimmar Rocketway Exchange

Foreman Fisk (29.2, 66.6) gives you:
A Quota to Meet

Horzak Zignibble (29.0, 66.2) gives you 2 quests
Stone Cold and Basilisk Bashin'
The first starts a chain which leads to:
The Perfect Prism
Prismbreak
Refleshification

These will unlock Private Worcester's quest, Another Warm Body which will send you to the next chain.

You need to do the quests for everyone at this new outpost on Forlorn Ridge (north of the rocketway exchange)

Commander Molotov (29.4, 57.6)
Hand-me-downs

Xiz "The Eye" Salvoblast
First Degree Mortar

Glix Grindlock
Military Breakthrough
In The Face!

Commander Molotov
Profitability Scouting
Private Chat

Now you can pick up the quest chain from Wrenchmen Recruitment Poster at Bilgewater Harbor
Operation Fishgut
Rapid Deployment
There Are Many Like It
Mop Up from Lieutenant Drex (41.4, 53.6)

You will also need to pick up Halo Drops from Sergeant Hort (41.4, 53.8)

Now you can get Lieutenant Drex's follow up quest, Field Promotion.

Once you turn this quest in to Captain Tork (34.4, 44.8) this quest will be unlocked.