The most common and most likely answer to this crossword clue is the 9 letter word REPAIRMEN
I've seen this crossword clue in The Sunday Telegraph
R
E
P
A
I
R
M
E
N
Buddy explains!
The straight part
We know that "mechanics, for instance" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case mechanics, for instance = repairmen.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does REPAIRMEN mean?
REPAIRMEN noun- A man whose job is to repair things