NEON FAULT 2002 TRANSMISSION

Hello, I have a good automatic neon my problem, my problem begins x a problem that I had on the radiator (I passed the transmission to the radiator) the problem was arranged and it manages it x 3 days until I check the level of the radiator oil and I did not have then the oil and from ai bino the fault is sweeping the changes or do not grab until after a few seconds as it is atora I no longer revolutionize what can I do ????
change the oil or .... ????