Green’s Dictionary of Slang

(US) an injury, a blow.

1922		Variety 28 July 5: The old soup bone was bad [...] I fixed his crock up by takin’ him to a local osteopath [HDAS].
1932		(ref. to 1918) F.W. Ward Between Big Parades 161: That was a whale of a ‘crock’ you handed him, ‘Smitty’ [HDAS].