クラッチが切れる 'the clutch disengages' uses 切れる (intransitive 'to be cut/severed'). なんとか 'somehow / barely' conveys the difficulty. 騙し騙し literally 'tricking, tricking' is a reduplicative adverb meaning 'nursing/coaxing a malfunctioning device along' — treating it gently and intermittently to keep it working. A vivid car-trouble narrative.