seal on rear of trany

[swamprat]

I got a 1996 F150 with an inline 6 and 5sp transmission. It is leaking out the back of the rear seal on the tail housing. I have been to two parts houses and the seal that they have given me do not look like what is on the truck. First one was too small and the other is too large. What is the right part number? The truck is 2 wd. The Haynes book is saying I have the m5od r2. Advanced says that it is th ZF. I believe it is the m5od because my drive shaft sides into the trany

 

[Explorin94]

It shows a ZF of a M5od-2

Part # is 14900

 

[swamprat]

taking it to a shop on monday. I have seen three differnt parts and none look like what I have.