Expérience GANIL/AGATA/VAMOS++ ; International audience ; Lifetimes of the 41+ states in 62,64Fe and the 11/21− states in 61,63Co and 59Mn were measured at the Grand Accélérateur National d'Ions Lourds (GANIL) facility by using the Advanced Gamma Tracking Array (AGATA) and the large-acceptance variable mode spectrometer (VAMOS++). The states were populated through multinucleon transfer reactions with a U238 beam impinging on a Ni64 target, and lifetimes in the picosecond range were measured by using the recoil distance Doppler shift method. The data show an increase of collectivity in the iron isotopes approaching N=40. The reduction of the subshell gap between the ν2p1/2 and ν1g9/2 orbitals leads to an increased population of the quasi-SU(3) pair (ν1g9/2,ν2d5/2), which causes an increase in quadrupole collectivity. This is not observed for the cobalt isotopes with N