I replaced the modulator and adjusted the pressure to factory spec about 3 months ago when I first got the car. Also at the same time I replaced most of the vac hoses and connections under the hood. The trans seemed to shift pretty good for its age, with a very small 3-4 flair.
One night after getting off the interstate 3rd gear just didn't engage. After trying to limp home for a couple minutes, I got angry I just gave it gas and all of a sudden it shifted and worked. The next day I changed the trans fluid/filter and added some Lucas. Now first thing in the morning it slips VERY bad going into 3rd and has a VERY noticeable 3-4 flair. If you floor it all gears engage solid, but it seems like it doesn't want to downshift and it seems to be shifting early too.
This sound like a vac or bowden cable adjustment or internal trans?