727 Tranny Problems I Think

OK I installed a 727 tranny in my Duster that was suppose to good . I filled the tranny a few days ago and moved the car from the lift into the driveway no issues . I decided to do a shake down run around the block last night and the car wouldn't hardly move , I let it warm up a bit more and got to move in reverse back into the garage . I searched my problem on FABO and found the seals are probably hard and in need of a rebuild . So I ran home today at lunch , started the car and it firmly went into R & D(cold) . I come home tonight and raise the rear wheels off the ground and again the car goes into gear firmly and seems to have no problem . The reason I raised the rear wheels up I had the idea of trying make it shift but in reality it seemed like a bad idea . I'm just wondering if anyone has had this issue on a freshly filled tranny and yes it is filled to the proper level .