94 sr5 4x4 automatic, 3.0

is it possible for the front tranny seal to leak only under certain conditions?

for example; truck does fine when not pulling anything, no slipping, everything works fine, maybe a drop or two of tranny fluid from the bellhousing occasionally, not enough to alarm me though. i do hear a noise first thing in the morning until it warms up sound kinda like a heat shield on exhaust but is coming from bellhousing/torque converter but goes away when things get warm

now pulling a load the other day and when i got home in noticed a lot more fluid at the bellhousing, matter of fact it was all over the passenger side rail even out to the inner front fender, at first glance i thought i had one of the lines leaking going to the radiator, but upon further inspection i can find nothing there, no leaks in those lines. so i added a little fluid i would say a 1/3 to 1/2 of a quart to fill it back up. now i am back to the same old drop occasionally that i had before. what do you guys think?