Gearboxes rhymes with:
xerox's, xeroxes, affixes, alex's, alexs, amax's, amex's, annexes, apex's, appendixes, avtex's, axes, banks's, boomboxes, brooks's, cevaxs, cineplex's, climaxes, coaxes, comex's, cox's, crucifixes, cyrix's, dax's, dynamics's, endotronics's, essex's, exes, faxes, felix's, fixes, flexes, genex's, hoaxes, imax's, index's, indexes, ionics's, isomedix's, jukeboxes, knox's, lynxes, mailboxes, marks's, matchboxes, matrix's, matrixes, max's, metroplexes, miramax's, nixes, nynex's, onex's, outfoxes, paradoxes, patlex's, perplexes, phoenix's, relaxes, royex's, sachs's, saks's, six's, sixes, skyboxes, sox's, speakes's, spinks's, surtaxes, syntex's, tax's, taxes', telex's, telmex's, vaxes, waxes, wickes's, x's, x.'s, x.s, xerox's, xeroxes
Gearboxes sounds like:
garbacz, garbage, garp's, garps, gearbox, geographic, geographic's, gerbasi, gerbig, gervais, gervase, gervasi, gervasio, giraffes, graboski, grabowski, grabs, grabski, graffius, grapage, grapes, graphic, graphics, graphics', graphs, graves, graves's, gravies, gravois, grbavica, greaves, grieves, grievous, griffey's, griffis, gripes, grips, grivas, grooves, groppy's, group's, groupies, groups, groups', grove's, groves, grubaugh, grubbs, grubs, gurevich