A breakdown can lead to strain on it (7)
I believe the answer is:
towrope
'a breakdown can' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'strain on it' is the wordplay.
I cannot quite understand how this works, but
'on' could be 'to' and 'to' is found within the answer.
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is present in the answer.
This explanation may well be incorrect...
'lead to' is the link.
Can you help me to learn more?
(Other definitions for towrope that I've seen before include "Cable for hauling vehicle or vessel" , "AA might assist with this" , "What may pull broken-down vehicle" , "Cable used after breakdowns" , "Pulling cable" .)