Is the 'PTU seal' included in a full PTU replacement or is it a separate part?

http://www.fordedgeforum.com/topic/2084-ptu-seal-failure-why/ What happened? Why a new unit. Get a second opinion.

I asked the Ford Mechanic working on my 2012 Edge what exactly happened. It turns out the APU is its own isolated unit with its own unique type of gear lube that is NOT LV class transmission fluid. When the seal fails between the APU and Transmission the LV transmission mixes in the APU and overfills it causing what appears to be a "Tail Shaft Seal" leak. However, there's a small vent on the APU that leaks out the mixed and contaminated fluid. Once this fluid mixes in the APU it's game over. The unit needs to be completely replaced. We were lucky and our Power Train Warranty replaced it at 40000 miles.