We investigate the differences in theΛseparation energies (SΛ) of the ground and superdeformed (SD) states in 37 Λ Ar, 39 Λ Ar, and 41 Λ Ar within the framework of antisymmetrized molecular dynamics (AMD). In this study, we find that the calculated SΛ values in the SD states are much smaller than those in the ground states, unlike the result using the relativistic mean-field (RMF) calculation [B.-N. Lu et al., Phys. Rev. C, 89, 044307 (2014)]. One of the reasons for this difference between the present work and the RMF calculation is the difference in the density profile of the SD states in the core nuclei.We also find that the property of the ΛN odd-parity interaction affects the SΛ trend between the ground and SD states.