One problem related to rear suspension leaf spring hanger/bracket has been reported for the 2006 International 9900. The most recently reported issues are listed below.
Spring hangers on our International 9900i trucks, on the rear drive axles have been cracking and breaking into two pieces. We have had 2 or 3 so far that have broken. If they are not caught in time the axles could move out of alignment and cause the truck to dog walk out of their lane of travel.