Nissan Repair: PU Transmission, torque converter, auto transmission

Question
I have a question concerning a 91 Nissan PU with an auto transmission, with low miles. About a week ago the trans. started whining, and eventually quit moving in all gears, and would only move after shutting off the engine for a few minutes. I removed the trans pan and the filter appeared plugged, and an excessive amount of oil drained when the filter was removed. The pan was clean, and the oil did not smell excessively burned. I replaced filter and new oil, worked fine until today, about 600 miles, and the problem is coming back. Any suggestions?
Thanks
Rod

Answer
Rod,

If the fluid was gummed up you could need to replace the filter again.  Polyester filters are great at keeping fine particles out of the valve body.  But, they do plug with varnish and gummed up fluid.  The excess amount of fluid you describe is normal since most of the fluid is in the torque converter.  I would replace the filter again and hope for the best.  You should need about four quarts to top it off.  Never overfill or underfill the transmission.  Check it running on a flat surface, at operating temperature, in park.