1994 trans issues
 

My 1994 has 75k miles. Last couple of days it felt "off". Seemed like it was pulling okay right from takeoff, but like it was holding back a little from 40-60 mph. This morning I lost third gear. First, second, then revs high and doesn't pull, just slips. Occasionally feels like it grabs for a few seconds then revs high again. Turned around and went back home a distance of three miles. Fluid doesn't look very dark, no strong burning smell, and level is on the mark. Never got it over forty so don't know about a 3-4 shift.
Would it be worth dropping the pan and looking for sediment, maybe changing the solenoids? Any way to check the solenoids, especially the EPC one? Or just figure on the 3-4 clutch pack needing replacing?

My experience with the 4l60 and 4l60e is simple. When it does this in the C4.
Check fluid. If color is pink, thats a plus.
The transmission is a E version, meaning its electronically adjustable, via tuner for harsher shifts etc. If none of this has been done, you lost 3rd, the transmission is probably dying. I have lost several 4L60 right after 3rd went away..
At your mileage, I would at a very minimum, change fluid and filter..
Solenoids. Thats a tough one. If they get stuck, they wont work. But, that is why I recommend a filter/fluid change, to start.
If you are going to change anything in the clutch packs etc, might as well rebuild the whole thing with far superior parts, like from Dana at ProBuilt automatics.
Dont drive it anymore..
4L60/Es weakness is 3rd/4th gear band..