Fidel:
The chucks are all interchangeable between the old C 12, the TDK, the old T series and the new Li-Ion drills except the CXS. The CXS has a different mount for its right angle chuck. So, the right angle, eccentric, and depth-stop chucks can't be switched between the CXS and other drills.
Between the TDK, C 12, T 12, T 15, C 12 Li, C 15 Li, T 12 Li, T 15 Li, and T 18 Li, the chucks are interchangeable.
Tom