What does it mean to dream about wrench?
A wrench usually stands for adjustment and the means to set something right, so it helps to ask whether it fit the job or slipped uselessly.
Four ways to read it
Each reading below comes from a named tradition and a cited source, so you can see where it came from and decide what fits your dream.
Freud
Freud would read the tool gripped to tighten or loosen as an image of control over a stubborn thing, the wish to master what resists. Forcing it can carry the strain of an effort that will not give.
After Freud, The Interpretation of Dreams (Brill trans., 1913), public domain.Jung
Jung might see the wrench as the means of adjustment, the tool that brings a part of the machinery of life back into true. Reaching for the right one can mark a search for the fix a problem needs.
Jungian concept (our summary).Modern
Continuity ties a wrench to waking thoughts about fixing, adjusting, and finding the right tool for a stuck problem. A wrench that will not fit often echoes a real sense of using the wrong approach.
Continuity hypothesis (our summary).Mythological
The craftsman's right tool runs through myth as the instrument that mends and makes, the means by which the smith set the broken world to rights. The skill lay as much in choosing the tool as in wielding it.
Rosmerta Publishing editorial synthesis (after Bulfinch; Brewer).