HVAC Blend-Door Actuator Gear

Internal replacement gear for the original blend-door actuator used in the creator’s ML 320. The source identifies A1638200108 as the complete actuator, not as this printed child gear, so that parent assembly number is not assigned. The creator warns that aftermarket motors may differ, tolerances are very tight, and sizing may need adjustment. Print in ABS at 100% infill; PLA is explicitly not recommended. Mark the metal-shaft position before disassembly, reinstall the gear with the flat side up, and preserve the original actuator orientation.