FORD 2011 F-550 v.4 - Manual (Page 213)

WARNING: Failure to inspect and if necessary replace the
safety belt assembly or child restraint system under the above
conditions could result in severe personal injuries in the event of a
collision.
Seating and Safety Restraints
213
2011 F-250/350/450/550 (f23)
Owners Guide, 4th Printing
USA (fus)