no..not yet. I would wager it is the o-ring on the rear servo pin leaking MAKING you think pan gasket.

brake clean and baby powder will tell the tale.

I have brake cleaned it well and rtv the end of the shaft up and let cure. 50/50 chance it seals.

might as well run a wrench on all of the tail housing adaptor to trans housing bolts & adaptor to xfer bolts.

the 727 tailhousing adaptor has a paper gasket but I have found the o-ring on the servo pin to be the most common leak as it is always over looked on a rebuild.

check the NSS plug, the coating on the washer will wear and leak on top of the pan rail also.

have you ruled out the gear selector shaft and PTK shaft seal? again brake clean and baby powder there area this leak shows up sitting over night as well as when driving. so run to temp/clean/let sit over night.

LARRY PM me you # and I will text you a couple pics pointing out the spots I refer to. (pivot pin) then you can pin point them under your truck.

I have run thru a couple cans of brake clean. I will continue to clean it up. So much crud built up from years of neglect. The leaking freeze plug at rear of engine (that I replaced as soon as I got truck) for years that kept everything underneath wet, collected tons of dirt, along with the other leaking fluids.

Thanks Mike. Sending my number now.

you can use some purple cleaner and scrub brush then rinse with water save the brake clean to remove the oil film when done.

Thanks. I have been using some Simple Green too, along with a paint scraper, it's just hard to get on top and in the little nooks and crannies. I think bottom line is I'm going to have to pressure clean the layers of neglect away.

LOL! yep been there. after a day of mudding in the swamps I used to lay under mine with a hose and brass 1/4" cone nozzle to wash all the mud out of the frame and off the drivetrain. be sure to wear a dive mask or goggles under there pressure washing.

I used a steam cleaner when I had the trans/range box on a trans jack and the xfer got it while on a floor jack.

it is a little bit of work to R&R the trans/xfer but a good HD trans jack along with a floor jack & solid slab to work on it can be done in a day.

I always hated R&R of the xfer shifter and mount bracket and it was always HEAVY WORK!

Obviously, the previous owner skipped the R&R but not the off roading fun!