You da man. I have just been babying my tranny a LOT... If it persists I will drop the service pan and get the bits I can do under there... If that doesn't work, I'm def going to try a rebuild w/o dropping it like you said... Do you have lift? How did you get under there?
I hope it keeps running but I'm thinking this isn't a 300,000 mile car or transmission at least lol I'm hoping I can get 200k... My truck has 225k and is running strong.
I put my car up on blocks. I have some 10x12x14 wood blocks that I set up on the 14" dimension, with a 4x6 about 4 feet long laying across them. That was all placed on the main structural beams built into the unibody just behind the engine-cradle. This puts the front end about 16" higher than normal. The only thing you have to work underneath to perform is the pan/filter drop and possibly add a couple upgrade parts in the pan (IIRC there are 2 accumulators in the pan if you were to add shift-kits to them). The rest of the work will be done from the driver-side wheel well. Unlike a longitudinal transmission, the transverse transmissions have the valve-body and all the goods inside the end-cover which comes off the driver-side of the transmission. You pop the driver wheel assembly out including the strut, lower the cradle down to get more clearance, loosen all the bolts on the end-cover, then play a jenga game to get it out. You'll be looking at the valve-body. Removing the valve body will get you access to the clutches.
Note: Do LOTS of research on common problems with these and what to look for. The reason I did mine was my 4th clutch hub shaft stripped the splines (common problem pre-03). I didn't have any other options so I was forced to drive it to work for the next 4 days like that. Amazingly, the day before I stopped driving it started experiencing problems associate with the worn input clutch piston. I had no idea it was a problem so I had no idea to look at or inspect the piston for wear. Thankfully that problem arose and I got a reman input piston 2-day shipped so I could complete the in-car rebuild that weekend. See here for what I'm talking about, I suggest you look through a lot of his pages of common problems. He's a 4T65E guru, he answers the phone, and his parts are GTG if you choose to buy from him.
http://tripleedgeperformance.com/No-Forward-Cold.html
Whatever you do, take your time and be very, very thorough. I thought I was thorough but I was rushed, it was my only wheels and I did it over a weekend in my driveway. Sunday night it was getting dark on my as I finished up. I put the last few parts in the tranny by head-lamp. I forgot to put the chain splash deflector thing in. I set in on top of my blocks wrapped in a rag so I wouldn't forget it; it was RIGHT there. But by the time I got to that it was dark and that was out of view because my headlamp was shining at the transmission, not the block it was sitting on. So I got to pull the end-cover again to put that in... got it all buttoned up and took it for a test-drive at midnight... Limp mode.... son-of-a-*****... I was pissed... but I had to have it done so I could go to work in the morning. It was throwing a solenoid circuit failure code... I drop the cradle and check all the solenoid connectors... apparently I didn't get one of the clicked all the way on... simple problem, 5 hrs to fix it. By the time I got it all back together it was time to leave for work and I hadn't slept yet... I called in sick. Thinking back, I should have just stopped when it got dark because I was starting to get rushed and frustrated, and that's NO time to be working on something so critical. Call me a retard, amateur, whatever, I know I made stupid mistakes, but I didn't plan to. I'm usually very thorough when it comes to things like that but lack of sleep, frustration, and a bit of anxiety about getting the job done and it's easy to make silly mistakes like that. Just trying to save somebody else from repeating mine.
ETA, one more VERY VERY IMPORTANT thing. DO NOT torque the bottom 4 end-cover bolts to the spec listed in the service manuals. It's a known weak point, google it. 99% of people that are going to have problems have the cover crack immediately so they know there is a problem. I was the unlucky 1%. I rebuilt it, drove around a couple thousand miles, then set out on a cross-country road trip (travel for work). I drove all the way from Indiana to New York, drove around New York for a week, then got 80% of the way back to Indiana (very lucky I made it that far) and transmission started slipping (I had put at least 4k miles on it since rebuild at this point). I pulled off at the next exit and tranny fluid is running out the cover in a steady stream. I jack it up, pull the wheel, crawl under and I can see the crack right around the bolt hole. It was after that happened that I found out it's "common knowledge" that you don't torque those bolts to the spec listed in the manual. F*** Me... $40 for an end-cover on ebay, already pulled and cleaned, it's just the 5 hrs labor to jack it up, lower the cradle and swap the covers out.
This was all a few years ago. IIRC it was around 228k miles when I did that and I just rolled over 250k miles last week.
Small tid-bit, if you aren't familiar with GM transmission lingo. The first number is the number of speeds (4), the letter is transverse (front-wheel drive) vs longitudinal (rear-wheel drive), the next 2-digits is the torque rating (number value is arbitrary I believe), and an E at the end indicates electronic controls. IE, 4T65E is 4-speed, transverse, 65 torque rating, electronic controls. The thing that I'm not sure of is if torque ratings can be compared between T & L transmissions. IE, your car with a 4T65E has less torque and power than a Yukon with a 4L60E... is that why the 4L60E's have issues?