TH400 issues with no gears

[madd0nk3y]

I had a TH400 that was dripping really bad in my 86 C30. So I decided to replace the seals. I ended up replacing the front pump seal and the O-ring around the Oil Pump and gasket. It was running perfectly before hand and when I re-installed it it was sluggish. At that time I just moved it about 10 feet and parked it as it was getting late and all gears were grabbing. The next morning I checked for a leak and nothing so I tried to drive it around the block. Took off kind of hard but it went. It did not make it around the block so I parked it and walked home to get my tools. I came back checked the tranny fluid, clean and full enough (read a little low) added 1/2 qt. Tried all Fwd and reverse gears and nothing.

Called friend over to see if he would help me push truck back. When he showed up, it took off under its own power so I drove it home but could feel it slipping really bad. Dropped the pan and it had metal sludge around the magnet and the bottom of the pan and new filter.

Checked online and read that maybe I did not seat the torque converter correctly, but this is just a wild guess.

What I would like is to get my truck moving again, I bought the ATSG and checked the following "NO MOVEMENT ANY RANGE"
Fluid Level...OK
Oil Pressure...Did not check before removing
Manual Linkage...OK
Torque Converter...Not sure how to test out of vehicle.
Transmission Internal...Afraid of damage because of sludge.


What could have happened? What can I do?

I bought a used TH400 off CL but have yet to attempt to install it with a brand new TQ converter.
I doubt the used tranny is going to work but with the new tq conveter I figured it was worth a shot but was told it had sat for 6 years.