Ƙunƙarar tuƙi, wanda kuma aka sani da "ƙahon tumaki", yana ɗaya daga cikin mahimman sassan tuƙi na mota, wanda zai iya sanya motar ta tsaya tsayin daka da canja wurin tuƙi cikin hankali. Ayyukan ƙwanƙarar sitiyari shine watsawa da ɗaukar nauyin gaban motar, goyan baya da tuƙi ta gaba don juyawa kusa da kingpin don kunna motar. Lokacin da abin hawa ke gudana, yana ɗaukar nauyin tasiri mai canzawa, don haka ana buƙatar samun ƙarfi mai ƙarfi.
An haɗa ƙwanƙarar tuƙi tare da jikin abin hawa ta cikin bushing uku da kusoshi biyu, kuma an haɗa shi da tsarin birki ta hanyar rami mai hawa birki na flange. Lokacin da abin hawa ke tuƙi cikin babban sauri, girgizar da ake yadawa daga saman titi zuwa ƙwanƙolin tuƙi ta hanyar taya shine babban abin da muke la'akari da shi a cikin bincikenmu. A cikin ƙididdigewa, ana amfani da samfurin abin hawa na yanzu don amfani da haɓakar ƙarfin nauyi na 4G ga abin hawa, ƙididdige ƙarfin amsawar tallafi na maki uku na bushing na ƙwanƙolin tuƙi da wuraren tsakiya na ramukan hawa biyu na aron kusa kamar nauyin da aka yi amfani da shi, kuma yana iyakance digiri na 123456 na 'yanci na duk nodes akan ƙarshen fuskar flange da ke haɗa tsarin birki.