98 Sebring Convertible, Transmission Noise, GOING NUTS!!!!

Hey guys. I have a issue with my car. I just put a new engine and transmission in her. Well not new, a garunted engine and transmission. The engine had 58k on it and the transmission had 60k on it. Now, it has been in the car for a little over a week. Now, tonight i was driving her, and after abt 15 min of driving i started hearing this whizzing/whining sound coming from the transmission. Then, it starts to slip ever so slightly. Then, when i turn if off for a few min, literally a min or 2, i turn it back on and drive away, and nothing, but after driving it again for abt 10 min the whine/whizzing noise comes back. Whatever it is, it feels as if its starving the trans from fluid and causing it to slip. Im thinking somthing is in the trans fluid and clogging the pump, bc when i turn it off for a min and turn it back on, it goes away for sometimes 5 min, somtimes 10 min. It really is weird. Idk if this matters, but i never did the trans filter when i put it in, and im regretting it now, and i used all new ATF +4 since ATF +3 is pretty hard to find and it said it was safe for the chrysler transmissions. Maybe you guys can help, im at a loss with this one. Thanks for the help!!! :banghead:

sound like a front pump and converter failure pretty common

Hey man, thanks for the info, I actually found out that it was my filter was clogged up, changed it, and its been running great every since. Thanks for the help tho, it pointed me in a direction.