In the middle of a 4x4 trans swap. Drained the oil, which was burnt, and very dark. Opened up the pan, and there was thick milky oil on top. When I went to wipe it, the bottom was virtually metallic goop. Looking up in the trans it looked really good and clean (not that you can see much) besides the burnt oil.

Obviously the previous owner of the trans, had a radiator failure and failed to tell me, so the trans is absolutely gone. I'm not sure what exactly happens when coolant is introduced to a trans, but the amount of metallic oil in the pan (no major chunks, just fine "dust" I guess you could say) tells me something somewhere inside is gone.

My question is, I threw my old torque converter from my 2wd trans in it, which still worked just fine. It has a new radiator in it. If throw it back together and run it for a bit, will that cause further damage to the torque converter and throw trash into the radiator?

Mind you this is a project so I'm not in too terrible of a rush. But I would like to be able to move it around under it's own power while I decide my next move and finish other details on vehicle.