general problems of the 2002 Ford Excursion

My husband was buckling our 3 year old in her car seat in our 2002 Excursion and the seat belt detached from the frame of the car. Left 2nd seat: seat belt bolt (location-retractor attached at frame) was either not properly tightened, locked tight improperly applied or nut is ill-fitting causing nut to separate from bolt, possibly related to pivoting retractor design. Seat belt detached at retractor and became unusable. Fortunately discovered while car parked and buckling child into booster seat. If accident would have occurred prior, seat belt would have separated and failed, and child would have been injured or killed! locktight was re-applied and nut was re-attached to bolt at proper torque.