I would replace the oil pan gasket, oil pump and pick up tube while you're in there anyway. If you have a little ability it really won't be a big deal

 

welcome to df.
don't overly panic about a leaking rear main seal. every older, high mileage dodge leaks from that seal, and most are not a big problem.

check your oil on a regular basis, daily or weekly.
monitor where you park - how big is the wet spot.
keep the oil level full and don't worry about it.

when you do decide to fix it, do this-
http://www.pavementsucks.com/tech-article-31.html

 

The odd thing is that I don't have any puddles or even drips under the truck. But when the truck was on the lift I could see that the tranny pan was soaked. Not sure how long it has been leaking. Think it is very serious?

 

If it doesn't leave evidence in the driveway, it isn't leaking that bad.

Are you sure it isn't the trans that is leaking? Pan seal leaks are pretty common.

 

no.
just check the oil regularly and keep it full,

 

+1 , check the trans pan bolts. 13ft lbs.

 

i have drops of oil on my tranny, so i figure its the rear seal, but a post says to search it for other threads, i cant seem to find them,, and a diy ? i cant find that either.. this forum is so full of good advise, though i am no mechanic. not even close... some say tranny has to be dropped, others say nope.. ill go with you guys on here and say nope,, take oil pan off and pop new one on.. i would like to find other threads though,, im not so good as navigating this forum yet.. helllllpppp...

 

Here: http://www.pavementsucks.com/tech-article-31.html