| 1 | VOLX | American Colloid Co. | added 4/1963; 7/1965-10/1966; eliminated 7/1967 | | NAKINA |
| 2 | VOLX | North American Car Corp. | added 7/1967; 4/1970-1/1980; eliminated 1/1984 | | NAKINA |
| 3 | VOLX | General Electric Railcar Services Corp. | added 1/1984; 1/1994; eliminated 10/1994 | | NAKINA |
| 4 | VOLX | American Colloid Co. | 7/65-10/66; eliminated 7/67 | | NRHS |
| 5 | VOLX | North American Car Corp. | added 7/67; 4/70-1/80 | | NRHS |
| 6 | VOLX | General Electric Railcar Services Corp. | 1/94; eliminated 10/94 | | NRHS |
| 7 | VOLX | (NATX) GE RAIL SERVICES CORP. - AMERICAN COLLOID CO.-LESSEE | | | PWRC |
| 8 | VOLX | GE Rail Services | | | RSRV |
