Any 700r4 gurus?

BLACKMAX1

WAY2EVL
Jul 10, 2013
555
6
18
VA beach
Sup guys, I have a 1990 K5 and while driving in second gear the truck will rev as if its in neutral and not shift into 3rd. Fluid was low so I topped it off with no change also adjusted the TV cable. I'll be dropping the pan tomorrow and changed fluid/filter and see what I find, I've read that the c3/4 clutches may be shot. Any other ideas?
 

BLACKMAX1

WAY2EVL
Jul 10, 2013
555
6
18
VA beach
Didn't smell bad. It was just low and even full looks a little dirty, not burnt but particles/sediment in it. Haven't been able to drop the pan yet, hoping tomorrow ill be able too. I'll report back.