Zida zozungulirapinion shaftimagwira ntchito yofunika kwambiri pakugwira bwino ntchito kwa ma gearbox a helical, omwe amagwiritsidwa ntchito kwambiri m'mafakitale monga magalimoto, kupanga magetsi, ndi kupanga. Ma gear a helical ali ndi mano opendekera pa ngodya, zomwe zimathandiza kuti mphamvu ifalitsidwe bwino komanso mopanda phokoso poyerekeza ndi ma gear odulidwa molunjika.
Pinion shaft, giya yaying'ono mkati mwa gearbox, imalumikizana ndi giya yayikulu kapena seti ya giya. Kapangidwe kameneka kamapereka mphamvu yotumizira mphamvu zambiri komanso kugwedezeka kochepa komanso phokoso. Kapangidwe kake kamatsimikizira kugawa bwino kwa katundu m'mano angapo, zomwe zimapangitsa kuti makina a giya akhale olimba.
Zipangizo monga chitsulo chosungunuka kapena chitsulo cholimba nthawi zambiri zimagwiritsidwa ntchito popanga ma pinion shafts kuti athe kupirira katundu wolemera ndi kuwonongeka. Kuphatikiza apo, ma shafts awa amapangidwa mwaluso kwambiri komanso amatenthedwa kuti atsimikizire kuti ali bwino komanso kuti ntchito yawo ikhale yayitali.