Ford 2002 Excursion Owner's Manual page 115

Driver controls
To adjust the tie-downs:
Use the adjustable tie downs to secure loads to the luggage carrier.
1. Completely loosen the slider knobs at each end of the cross rail.
2. Lift the cross-bar and re-set it at the desired position. Ensure that
both sides of the cross rails are even.
NOTE: Siding the cross-bar on the roof can cause damage to the
roof paint.
3. Tighten the slider knobs at both ends of the cross-bar.
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