I've replaced the transfer case rear output seal three times in the last year. I noticed fluid on the garage floor this morning.
It's a 2009 Ram 1500 TRX4 Crew Cab, Hemi and automatic with 74,000 miles. It has lead a pretty easy life.
When I replaced the seal the second time, I took the yoke to a local drivetrain shop to see if they could see any problem with the surface that would cause this problem. The seal surface is smooth and no groove. He checked his parts listing to see what a replacement would cost, then announced, "Let me look inside that damn thing. Returning to the part description he said, "That #@=%& thing is too short!" His theory is the yoke is only engaging the end of the spline output shaft and has worn enough to wobble a bit and take out the seal.
How could this be possible??? It would have to be a factory screwup. Should I buy the listed yoke and try it?

 

Think I would chat with the dealer, see if they have the correct one on the shelf, (doubtful) and see if there are any differences..... Might also check the bushing in the tailhousing of the t-case, and see if it is worn, allowing more slop than it should.