The magnitude of the single-crystal elastic constant c(44) in the MAX phase Ti3SiC2 is under debate. In this paper, estimates for the magnitude of c(44) for MAX phases Ti3AlC2 and Ti3SiC2 are determined from a partially oriented polycrystalline sample via coherent inelastic neutron scattering. The largely quasi-isotropic nature of these M(n+1)AX(n) phase elastic constants as previously predicted by density functional theory calculations is confirmed experimentally for Ti3AlC2 to be c(44)=115.3 +/- 30.7 GPa. In contrast, Ti3SiC2 is confirmed to be shear stiff with c(44)=402.7 +/- 78.3 GPa supporting results obtained by earlier elastic neutron diffraction experiments.