ʻO kahi pahu worm he mea nui he mea nui i loko o kahi gearbox i kahiʻano o ka gearbox,ʻo ia keʻano o ka gearbox e loaʻa ana kahi huila worm) a me kahi wīwī worm. ʻO ka pahu worm ka lāʻau cylindrical ma luna o ka mea i kauʻia ai ka wī. ʻO ia ka mea maʻamau i kahi kaula helile Hana pinepineʻia nā loleʻino i nā mea e like me ke kila kila kila a iʻole nā ​​mea koi, e pili ana i ka ikaika. Ua hana pololeiʻia lākou e hōʻoia i ka hana kūpono a me ka hoʻohana ponoʻana i ka mana kūpono i loko o ka gearbox.