This bus fits into the stub axle and king pin tube

Express L6 ELITE, Express S4 ELITE, Express S4 HO, Hauler 1200, Hauler 1200X, Hauler 800, Hauler 800 ELiTE, Hauler 800-E, Hauler 800X, Hauler 800X ELiTE, Hauler 800X-E, Hauler PRO, Hauler PRO X, Hauler Refresher, LSV 800, Refresher FS4, RXV Fleet, RXV Freedom, RXV Freedom ELiTE, Shuttle 2+2, Shuttle 2+2 HS, Shuttle HS, TXT Fleet, TXT Fleet ELiTE, TXT Freedom, TXT Freedom ELiTE, TXT Shuttle 2+2 EFI, TXT Shuttle 2+2 ELiTE, TXT Valor, Express L6, Express S4, Express S6, Freedom, Shuttle 6, Shuttle 4, Shuttle 2, Shuttle 8