Left in church? Fix the wheel securer? (8)

I believe the answer is:

linchpin

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'the wheel securer?' is the definition.
I can't judge whether this defines the answer.

'left in church? fix' is the wordplay.
'left' becomes 'L' (common abbreviation).
'church?' becomes 'ch' (common abbreviation).
'fix' becomes 'pin' (pinning is a kind of fixing).
'l'+'in'+'ch'+'pin'='LINCHPIN'

Can you help me to learn more?

(Other definitions for linchpin that I've seen before include "Person or thing essential to plan" , "Vital ingredient" , "One is essential to a plan" , "Pivotal character" , "It keeps wheel in position on axle" .)

I've seen this clue in the Sydney Morning Herald.

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