While investigating our clicking/grinding issue with a Falcon, we found all 5 of the screws that held on the spline shaft had no traces of loctite. We then opened up 20 Falcons we bought this season.
1/3 had no loctite on any screws.
1/3 had loctite missing from a couple screws. Some of the ones with loctite were minimal.
1/3 had loctite on all screws.
Check your motors folks.