Gears in the Deep Roads

Gears in the Deep Roads is a collection in The Descent DLC for Dragon Age: Inquisition.

"Bloodstained ancient gears are scattered throughout the various regions of the Deep Roads. Collect them to open Gates of Segrummar, revealing the secrets within."

Acquisition
After you open the gate in the quest Rune-Warded Gate of Segrummar, you'll enter a room and fight some darkspawn. Exit that room, going forward, and then use the search tool. The first gear should show up on your map and/or screen. Collecting it will start the quest. (Note: obtaining any gear will trigger the quest, this is just the first one)

Darkspawn Warrens
''Note: Despite the fact that the area you are in for 7 and 8 is labeled as Ruins of Heidrun Thaig, these two gears still count as Darkspawn Warren gears. ''
 * 1) This is the gear that starts the quest. Go to Acquisitions to figure out how to find it.
 * 2) From Gear 1, go straight down the steps and then turn left. It is a dead end. Use your search tool and the gear should pop up on your map and/or screen. It is located behind the third giant rock from the left. Pick it up.
 * 3) From gear 2, turn around go straight until you are next to a pile of rubble, This pile of rubble is right across from a light source that is next to an exit. Use your search tool and the gear should be behind the pile of rubble. There is also some Rashvine next to this gear.
 * 4) This gear is located in the same room as 1-3. It is next to the light source that is on the right of the giant doorway with no door. If you've not completed the story, Valta will mention that this is the way to go in order to progress the main story quest. There is also a gear door that is right by this gear. Use your search tool, that thing works wonders.
 * 5) The next gear is a little tricky to get. Follow down the giant doorway mentioned in 3. If you've yet to reach this part before, you'll encounter two darkspawn. This area is a little stone hall with a set of staris and a door at the end. Before going through the door, turn your camera slightly to the right and use your search tool to see the gear on a ledge. There is a big rock to the left of the door that you can stand on. Stand on it and then jump onto the railing (if you jump over that is okay, just try not to fall off) Now you will be walking out to the gear. To avoid falling off, move slowly.
 * 6) Keep going forward and you'll enter a room with several fires in it that makes the room look orange. There is some tough darkspawn in this room, so be prepared if you have not been here before. Starting from the entrance to this room, turn right and go down a small set of steps. At the bottom of the steps, turn left down another set about half way. At the bottom of these steps there are two fires. Look at the fire on the right and use the search tool to see the gear in the fire. Jump onto the railing and walk down it carefully to successfully reach the fire and collect the gear.
 * 7) To get this gear you must complete the expedition table mission Deep Roads Expedition: Heidrun Thaig Upper Bridge. It cost 8 power to complete. To acquire, you must place a landmark at the end of darkspawn warriors and Valta will inquire about the  that lay before you. So go down the wooden bridge and take the left path. It will lead you to a ladder you need to go up. Go past a giant rock and then turn directly right. You'll pass another gear door and then turn right again. You'll be walking on a bit of road. Go straight down a little stretch of path andturn right when you are able. Use your search tool, the gear should be directly in front of you.
 * 8) This also has the same requirements as gear 7. Starting from the gear door by gear 7: Return to the spot on the bridge where they split off. You will now go the other direction (which is left. Do not go up the incline of the bridge, that is just backtracking. If you did that, then you're turning down the right path) Keep going forward until you reach a set of stairs. Go down them and use the search tool. The gear is in front of the stairs on the left side,

Ruins of Heidrun Thaig

 * 1) Ignoring the elevator down, use the ledges past the elevator to start descending. The gear is on a balcony near two Dwarven boxes.
 * 2) North of where the elevator would have stopped, there's a gear.
 * 3) Hugging the eastern wall, find a gear before crossing the near by bridge.
 * 4) There's a gear on the bridge.
 * 5) Ignoring the next archway, drop down to the ledge east of the opening. The gear is on the ledge.
 * 6) Following the path from the previous gear, you'll find this gear by the treasure site for the quest On Broken Knees.
 * 7) Through the archway, you'll battle corpses. The gear is in the south-east corner of the chamber.
 * 8) There's a gear past the northern Gate of Segrummar in this chamber.
 * 9) South of the corpse-batttle chamber, near some Rashvine, there's a ledge that'll lead you upwards to a gear.
 * 10) Back in the corpse-battle chamber, there's a gear before you enter the western tunnel.
 * 11) There's a gear in the western tunnel.
 * 12) In the dead-end of the #11's tunnel.
 * 13) Same as #12.
 * 14) Same as #12.
 * 15) Same as #12.
 * 16) Follow the bridge near the next major archway. You'll  find 2 gears and a Dwarven Mug.
 * 17) See #16.
 * 18) Backtrack to the bridge's start; ignore the archway, and follow the ledge eastward. The gear is tucked underneath a rock on some tile.
 * 19) Before entering the chamber in which you will or have battled two Ogres and an Alpha Emissary, the gear is found in a tunnel at the north-end of the map. It's the same location as the last entry for the Killing Me Softly quest.
 * 20) Requires the Heidrun Thaig Lower Bridge operation to be completed. This gear is by a Gate of Segrummar.
 * 21) Requires the Heidrun Thaig Central Bridge operation to be completed. This gear is near the ladder that leads to a landmark.
 * 22) Require the Heidrun Thaig Upper Bridge operation to be completed. Drop to the ledge below the eastern ladder. Follow the path to a horizontal piece of a broken Dwarven bridge. The gear is on this piece of bridge.