After a Survivor loses a health state, Gearhead activates.

While Gearhead is active, the next time a Survivor completes a Great Skill Check while repairing, the perk deactivates and their aura is revealed to you for 10 seconds.

Your base Terror Radius is increased by 8 meters.

Whenever you are outside of a Chase, your Terror Radius is reduced by 16 metres while your Field of View is increased by 3/5/10 °.
Field of View gains do not stack.

While carrying a Survivor, you suffer no cool-down on missed attacks.
Successfully hitting a Survivor will pause the carried Survivors Wiggling Progression for 2/3/4 seconds.

The Scratch Marks left by Survivors spawn slightly/moderately/considerably closer together.

When a Survivor heals another  Survivor for one health state at least 32 meters away from the Killer, the Survivor performing the healing action will scream, revealing their location and activating Deathbound for the next 60 seconds.  During that time, the Survivor will suffer from the Oblivious status effect when further than 8 meters away from the healed Survivor.

Oblivious prevents the Survivors from hearing or being affected by the Killers Terror Radious.

When you hook a Survivor, Dead Mans Switch activates for the next 30 seconds.

While activated, any Survivor that stops repairing a generator before it is fully repaired causes The Entity to block the generator until Dead Mans Switchs effect ends.

Affected generators are highlighted by a white aura.