My A/T runnith over and grinds. Help!!

[PathFinder 007]

I just pulled and resealed the transmission in my 87 Pathfinder SE 3 Spd. Automatic. It was leaking badly and I couldn't afford to have it done by the guys with all the experience. After re-installing it, I tried to refill it. The mfg says that the transmission requires 12 quarts if it had been fully drained including the tourque converter. I started by putting one quart into the torque converter after draining it prior to re assembly. Next, I tried to put five more quarts in before I had got the engine running. The fifth quart of these spilled all over the floor. I figured that the pump would have to move the fluid through the transmission to make room for the rest. So I got the engine running and tried to put the other six quarts in. I got to the fourth quart of these and again the fluid started spilling out. The trany does not engage in any position. When I move the shifter from reverse to park I hear a grinding noise as the gears try to mesh and then finaly stop to allow the shifter to move to park. Does anyone know what's happening and what I am doing (or did) wrong. I,m still shy about 2 1/2 quarts of what the mfg. recommends and I don't know what to do at this point.

[PathFinder 007]

Called a local transmission shop and got my answer. Da! When I reassembled everything, I put the transfer case (4x4 Shifter into neutral) shifter into neutral. This causes the regular transmission to have nothing to turn (like the drive shaft or wheels) nor does it have anything to slow it down. When I shifted it into dive or reverse and the back into park the trany was still turning like when you try to shift into park while the vehicle is still moving and thus the grinding. The best I can figure is that there was still some trany fluid in the trany somewhere and the total fluid required to fill it back up was quite a bit (around two to three quarts) less than the total mfg. required amount specified. I just have now to remove the excess with a small hose thru the filler tube and a pump to attain the proper fluid level. This has been a learning experience but I figure I saved around $1000.00 in labor and now I don't have to worry about leaking fluid or running it too low an damaging it worse. Thanks for those who looked but didn't know what was wrong.