I've got a '79 f150 supercab 4x4 with a D44 front axle that I noticed that something appeared to be leaking under the middle front of the truck. After looking at it, I assumed it was the housing gasket on the axle. Went ahead and pulled it off, replaced the gasket and filled the axle back up with gear oil. Figured I had it fixed... A couple of days go by and I noticed that the leak was back. (Real slow leak though) So I went ahead and scraped all of the mud and junk off of the axle and dried everything off in hopes of finding the leak. Last night I took a look and this is where it seems somewhat strange. Nothing appears to be leaking on the top of the axle but it does appear that the leak is coming from what I would consider a strange spot.

If I'm looking at the front of the truck at the housing, on the left side about a couple of inches from where the gasket is, there is a "hole". It seems more like a hole from molding but in any case, the oil appears to be collecting in the bottom of this "hole". Nothing seems to be dripping into this spot, so I can only assume it might be coming from this location. Is this spot even possible to leak and if so how would a person go about fixing it?

If necessary, I'll post a pic, but figured I would ask first...

Thanks in advance!

-Jeff