Yeah, my impression is that “mechanistic” is often used in social sciences to refer to a very similar idea as “gears-level.” E.g. as discussed in this highly-cited overview (with emphasis added):
The idea that science aims at providing mechanistic explanations of phenomena has a long
history (Bechtel 2006) [...]. In philosophy of science, mechanistic explanation has been mainly discussed in the context of biological sciences [...] whereas in the social sciences the idea has been mostly discussed by social scientists themselves (Abbott 2007, Elster 1989, Elster 2007, Gross 2009, Hedström 2005, Hedström & Swedberg 1998, Manicas 2006, Mayntz 2004, Morgan & Winship 2007, Schmidt 2006, Tilly 2001, Wikström 2006). [...] In both contexts, the development of the idea of mechanistic explanation has been partly motivated by the shortcomings of the once hegemonic covering-law account of explanation (Hempel 1965). The basic idea of mechanistic explanation is quite simple: At its core, it implies that proper explanations should detail the ‘cogs and wheels’ of the causal process through which the outcome to be explained was brought about.
Yeah, my impression is that “mechanistic” is often used in social sciences to refer to a very similar idea as “gears-level.” E.g. as discussed in this highly-cited overview (with emphasis added):