Well, I finally got together with some friends who know more than I do and tracked down my oil leak (had to wait until it was cold out, I'm stupid that way)... As far as we can tell, the only visible oil leak (after cleaning up the engine bay) was from the bottom pulley located just above and in front of the oil pan. My friend identified this as the "Crankshaft seal", now I'm doublechecking to make sure that is right.

I'm heading back home for the holiday weekend and will hopefully get an opportunity to fix this, my stepdad thinks this is an easy fix, but he's never worked on a Ford before... so is this doable in a backyard mechanic sort of way? And what problems/procedures do I need to look out far while swapping in a new seal?

The truck is an '89 F-150 4WD, 300-I6, 4spd w/granny 1st...

Thanks guys... and Merry Christmas to all!

 

Matt,
Its not really a hard job ... Remove the belt and fan . Fan removal on the 300 requires a special tool . I suppose you can change the seal w/o removing the fan but with it out of the way you have a lot more room to work . About the best way to remove the pulley is to place a breaker bar on the nut and make sure the bar is firmly on frame or some solid part of the truck and simply bump the engine w the key ...And I do mean bump . If you have never done this before , make sure you know what way the engine rotates , If you are worried you may start the engine , just pull the coil wire off until you are finished ...place the bar so that it goes w the rotation. Usually a single tap of the key is sufficient to break the nut loose . Next step is removing the pulley . If youre lucky it will slide off but none of us are rarely that lucky . Chances are you will need a pulley puller . Once the pulley is off its time to remove the old seal . Have a good seal puller and or screwdriver to remove the seal, mine was fimly in place . I was the better part of 30 mins getting it out of the front cover . Be careful w the cover , its made out of some kind of pot metal and will break if you get too rough w it . The new Ford seal is designed so that it will not ride in the original place on the crank shoulder Make sure you dab some grease on the new seal so the new seal doesnt burn up on initial start. Tap the new seal in evenly and gently making sure it is snugly in the cover . To torque the crank nut , place the tranny in 4th gear and have someone hold the brake on to keep the truck from rolling as you turn the torque wrench . The rest is reverse of what you did . Good Luck