Part of tyre factory's routine (9)
I believe the answer is:
treadmill
'routine' is the definition.
(treadmill can mean a boring job or routine)
'part of tyre factory's' is the wordplay.
'part of tyre' becomes 'tread' ('tread' is part of 'tyre').
'factory' becomes 'mill' (synonyms).
'tread'+'mill'='TREADMILL'
(Other definitions for treadmill that I've seen before include "Walking or running exercise device" , "Drill team (anag) - routine drudgery" , "Dreary repetitive work" , "Boring or unending job" , "Power-generating wheel" .)