OK, thanks for the heads up on the thread. I've been getting better a checking for new threads daily at least once, and usually 3 times or more a day. So get off me fuggers !!!
To the problem, I not thinking it has anything at all do with the TC. It very well could, but I'm thinking no and would be suprised if it is. You mention you use an advance adapter to convert this trans to a Cummins 5.9. So let me ask this, how is the trans getting its vacuum from a diesel engine? Has someone installed a vac amplifier of sorts? Have they bypassed the need for a vac modulator with a cable to the throttle maybe? This is important, cuz its possible that your line pressure is going way to high and blowing he seal out. However, line pressure can blow out seals in other places, and I'd say its pretty tough to blow out the front seal. So then I have to wonder if there has been a mod made to the front pump and has possibly had a pressure bleed off blocked off? I'd also wonder if the pump gears may not be intalled upside down. Then, I'd also wonder how this advance adapter works. How far does the adapter let the converter come forward to match the flywheel? I think you're going to find that the problem will come with something to do with the Cummins conversion. Hopefully no big deal and something that can be rectified. I'll see if I can't do some research about a Th400 and a Cummins, and see if I can't find some info on this Advance Adapter.