92 Buick Regal Custom 4T60 leaking

I will give you a quick backstory. I have a 92' Buick Regal Custom 3.8 I picked up with 71k original miles because a fuel line had sprung a leak and the dealership told the owner it couldn't be fixed because they don't make fuel lines for this model anymore. So I got a good deal on it and just bought some fuel lines at autozone.

Anyways, ever since I got it the trans has clunked into second and third gear if you don't accelerate just right, but I had that down and have put 8k miles on it with regular oil changes and watch my fluid levels and all that and had no problems until a couple months ago it started missing when I put it in reverse. So I threw in some high mileage trans-ex and the slippage stopped and it ran fine for another month or so.

Then on my way back from California I was climbing a hill and suddenly the car wouldn't shift into third and I look down and my temp gauge is goin up and I pull over and my trans fluid is just pouring out the bottom. So I towed it into town and did a fluid change and a gasket kit because the leak seemed like it might be coming from the corner of the pan, but after I put the new gasket on it was still leaking pretty bad and it seems like it is coming from somewhere up inside the bell housing, but the engine takes up so much room it's hard to tell where.

So my questions are:
Is there a seal that is easy to access that may be causing this leak or does this sound like a problem you are familiar with?

What does removing this transmission entail? It looks like I would have to unbolt the damn frame to get this thing out to do a rebuild or replace it.

Is there a schematic available online that shows the 4T60 in detail and where/how it attaches to the torque converter and axles? I can't find one.

Any advice on this one? I would really appreciate it. This has been a great daily commuter for me, gets decent mileage and rides real nice. I'd hate to see her go.

Thanks
Travis

The only seal up in the bell housing is the front pump seal where the torque converter snout goes into the transmission. You have to pull the tranny to fix this. It is not an easy job and one that I would strongly advise it to not be attempted by amateurs that don't have access to a full shop. You are right there is a good chance to sub frame has to come out. The engine will then have to be supported from above while everything is out. I would have it professionally diagnosed and start calling around to reputable shops and get prices and warranty info and have the work professionally done. It sounds like the transmission has more problems than just a leak if it has been clunking into gear. I've had decent luck with chain store type transmission rebuilders.