If my unit gets rebuked, do the attached gears go back in my hand?

When your unit is returned to your hand (such as by the effect of the spell Rebuke), any gear attached to that unit does not return to your hand with it.

According to RiftJudge FAQ #2960: "When a unit with attached gear is returned to hand, the gear falls off and stays in the base, just like when a unit dies or is banished."

Additionally, Rule 422.4.b clarifies the zone change behavior: "If the Attached card was Detached because the Top-Most Card changed zones from a board zone to a non-board zone, then the location that the Attached Card will Detach to is the last location the Top-Most Card was at before changing from a board zone to a non-board zone."

Summary of the interaction:

1. Rebuke resolves, targeting your unit on the battlefield.
2. The unit is returned to your hand (a non-board zone).
3. The attached gear detaches and remains at the battlefield where the unit was previously located.
4. Per Rule 435.1, because the gear is now an un-attached card present at a battlefield, it will be Recalled to your base during the next cleanup.