95 PSD Oil Leak

[Seven_Three]

Hey guys i've got a 95 F250 PSD that has had an oil leak for the longest time. Finally today I decided to try and pinpoint it so I got look leak detecting dye and a UV light. I let the truck run for quite a while before looking for leaks the only place I could find the dyed oil was in this location (right behind engine oil pan and front of tranny.






I'm thinking rear main seal..? any other thoughts or ideas?
Thanks a ton in advance
BTW the Truck has 345k miles

[Gaius]

Look down in the valley to see if it's starting there. Generally the leaks will come from above the valley drains in the block at the top of the trans bell housing. Look carefully up around at the sides and top of bell housing. The pedestal can leak down without showing anything in the valley. The oil cooler also likes to leak. But the oil valley plugs and rear head plugs can also leak.

A little mirror helps to look under the pedestal.

[Seven_Three]

Ok good to know, so there is a plug in back of the head on the driver side? facing the firewall or what idk how i would access it if thats the case. I couldnt find any other leaks using the dye other than the bottom of the bellhousing of the tranny