Conversion vehicle shipments, which totaled 6,200 units, fell 34 percent compared with shipments in July 2000.
Pickup conversions took the segment's biggest hit, down 51.7 percent to 1,400 units.
Sport-utility conversions dropped 40 percent to 300 units. Van conversions fell 25 percent to 4,500 units.
Conversion vehicle shipments for the first seven months of the year were down 46.7 percent to 40,800 units.
Motor home shipments in July were down 18.9 percent compared with the same month in 2000.
Shipments of Class A motor homes, which totaled 2,000 units, fell 20 percent. Class C's also dropped 20 percent to 800 units. Class B shipments remained stable at 200 units.
Motor home shipments for the first seven months of the year were down 25.6 percent to 29,000 units.