'85 gt-s transmission

I have an automatic transmission and it slips a lot through first gear. I know i'll need to get a new trans., but can someone tell me whats causing it and where to find a solution. Thanks.

check the transmission oil. is it dirty or low? if it is try getting it changed first. my 85 celica with a40d auto tranny was slipping a lot when cold, I got the transmission oil changed and there was no problem after that. If that doesn't work, take it to the tranny shop and pay $90 for a diagnosis. Most likely you will need a rebuild or something else expensive...

my 85 gt was doing that as well, my torque converter was shot, so I just swapped to the w58 5 spd