DIAGNOSIS Rapid overheating under light load is abnormal. Primary cause is excessive friction from worn gears or a failing motor bearing.
FIX Isolate the issue. Run the tool with no load for 30 seconds. If it gets hot at the motor housing, the motor or armature bearing is failing. If heat is concentrated in the gear housing near the chuck, the gearbox has insufficient or contaminated grease, or gears are damaged.
IF THAT DIDN'T WORK An electrical fault can cause overheating. A shorted winding in the motor or a failing controller can cause the motor to draw excessive current, generating heat immediately. This requires motor or board replacement.
HEADS UP The tool has thermal protection, but chronic overheating will degrade plastic components and permanent magnets in the motor, leading to irreversible power loss.