Well to start so I don't get flamed I have been searching this site and some others for two nights now trying to find something or someone that has had the same problem I'm having. I haven't had any luck so here we go. I'm driving my car, took off from a stop light and was shifting manually and the tranny starts to slip in 3rd, then I shift to 4th and seems okay for a minute then it starts to slip. I'm thinking GREAT! I 'm just about to turn into my addition and thought that since I will be going slower to put it in 2nd. Well guess what slipping as well. I get to a stop sign and put it into 1st and take off and its slipping as well. I get to my house and tried reverse and it slips too. I get out and check the fluid and its dry I'm pissed by now because I had it checked by a transmission shop that was supposed to do a 21 point inspection on my transmission. Well I guess that they forgot one. So I get in another car and head to parts store and get some fluid and lucas transmission fluid and put that in and here is where it gets really dumb. I put the fluids in while the car is running and get into my car and put it in reverse and nothing. 1st and nothing. Back and forth and still nothing. I'm really not happy at this point, so I turn it off and go inside for a bit. Come back out alittle later and start the car and put it into reverse and it catches like its supposed to. Then put it into OD and it catches like its supposed to. Well I put it back into reverse to back up and guess what NOTHING AGAIN. So if I turn off the car, let it set for a minute and then start it again it will catch reverse and a forward gear and then back to reverse and nothing. So where do I start to run down the problem. Any thougts would be helpful I hope that I was detailed enough

This may or may not help, because my understanding of the internals of the 700r4 is still fairly basic.

It can't be related to the drum internals, band, or clutch packs. This is because L-R are one pack, and 2-4 are the other pack.

Maybe when you ran it dry you damaged the pump? So that it is balancing right on the threshhold of having enough pressure to operate the servo and pistons.

Or, maybe when you ran it dry it knocked some garbage loose and it's blocking a passage in the valvebody?

If you don't have the ability to tear the trans apart and diagnose the problem, it'll probably be cheapest to get a boneyard lower-mileage trans and swap it in. Then if you ever get the ambition to learn about what makes the trans tick, you can break it down and do a performance rebuild on it.

I'm betting the converter was empty too and when you filled it, most if not all of the fluid went there. Check your fluid level again with the car running, fill to proper leven and cycle the trans through ALL gears while sitting still, several times. Check fluid level again and repeat until it is reading full after cycling through the gears.