Differential gear has fallen out of my completed MCL39 build. Can it be replaced without stripping the entire model down?

The LEGO community is discussing a common issue with the LEGO Technic McLaren MCL39 set (42171): the differential gear falling out after the build is complete. A user, /u/Crewdragon22, initiated the discussion, seeking advice on how to replace the gear without completely disassembling the model.

Several users have offered suggestions. One user, /u/The_Brick_Builder, recommends removing the rear wing and the engine cover to access the differential. Another user, /u/Raptor_Racer, suggests removing the wheels and the rear suspension to gain access. The consensus is that some disassembly is necessary to address the issue, but a complete teardown might not be required.

The discussion highlights a potential design flaw or assembly issue with the set. While the exact cause isn't specified, the fact that the differential gear is falling out suggests it may not be securely held in place.

If you encounter this problem while building or after completing the LEGO Technic McLaren MCL39 (42171), consider the suggestions from the community to avoid a complete rebuild. You might also want to have a brick separator handy to help with any necessary disassembly.