possible TC failure?

OK, I am sure everyone is sick of my question about the trans. But I was reading another post that sounds about like my problem. He says that it is a torque converter failure.

I have had zero problems with my trans until my sonnax/tricum mod with amosil ATF. Went for a 600 mile trip pulling a 3000k boat in OD. While accelerating hard, started having a funky shift into OD only. All the other shifts are great! No problem! Now with the boat off, still having OD issues about 50% of the time. If I am not accelerating hard, it isn't bad. If I am even thinking about giving it juice, I get a bump, bump and it sets into OD. Are these symptoms of the TC going south? I have not noticed any of this TC rattle like some talk about. It is just amazing how all this could happen after a fresh synthetic fluid change.

What are the symptoms of a TC going bad? I really need to get this answered because I am freaking out about this! I do not have the finances to do a BTS or anything. Heck a TC is going to stretch my pockets bad.

Could anybody tell me if this is a TC problem or something else. I am sorry but I don't have gauges so I couldn't tell you if the temps were high. I surely don't think they were. 85 degrees while pulling and when it started gettting hilly, I just took it out of OD. If my 1990 1/2 ton truck can do that trip without burning anything up, I would surely think this beast could do it!!

Any help would be appreciated!