Torque Converter Issues?

[crazykn]

I'm actually posting for a friend of mine, who's too lazy to register and post. He owns a 1993 J30 (base) and his transmission has been having several problems. When he first purchased it, the transmission would shudder, slip, make all sorts of noises and have the infamous tunnel heat issue. Before declaring the transmission totally shot, we put in some AutoRX and drove it around for a while (1500+ miles) and then we flushed the transmission ourselves (yes flushed, not drained).

It cured nearly everything, but the issues left behind is some of the tunnel heat problem which occurs seldomly and we checked the fluid level, and its good. The other problem is that it seems like the Torque converter is slipping out at high speeds. He tells me that his J30 wouldn't go past 80mph (and I tell him why are you driving 80mph in a 65 zone ) the RPMs would suddenly jump and go wildly into the red. It feels like the torque converter suddenly slipped and reving itself out. It doesn't happen at lower speeds or gears. Could it be the Torque Converter not locking up?

Oh god, his car is almost like a project car to me... I wouldn't mind owning a J30 ... I currently own a Volvo 850 myself.