What's this?

I was under the Jeep poking around and came across this hole in the axle tube. Is this an original vent? There was very little oil seeping from it; barely enough to dirty a finger. Since the diff shop tapped a vent on top of the diff housing, should I just weld this up? Thanks guys.

 

there should be no hole in the axle tube, welding is possible.
might just spray it with degreaser/carb spray and slap a little black silicone over it. It was not a vent, the vent is on top as you know.
It appears to me that your brake line is rubbing on the u-bolt
might want to pull it out away from the u-bolt to stop the rubbing FYI

 

Thanks Jim!

 

Wait a second.....I distinctly remember there being similar holes in my
'57 when I cleaned it up and repainted it. It was a clean drilled hole, pretty obvious that it was a factory deal. Jim, are you saying that it shouldn't be there?

 

My 1956 D25 axle tube has a hole located about where the one in your pic is. The purpose is to anchor a brass tee fitting where the hard brake lines attach to either side of the block and the brake hose that goes to the frame attaches to the top. The block is anchored to the axle housing with a bolt that threads into the axle housing. The hard line that goes to the left brake needs a quick bend in it to miss the inboard spring u bolt. I just reinstalled mine yesterday, but haven't hooked up the new lines to it yet.

tommy b

 

Yes, mine has that too, but there is a distinct, small hole in my D44 rear axle.

Interesting....

 

The "T" fitting on the D44 rear axle on my '56 is mounted at the top of the pumpkin. The hard line from the m/c comes to the center of a rear frame crossmember, and from there it's a rubber hose down to the "T". Don't know if this is stock but I assume it is. There's still some scraps of the protective cloth covering on the hard lines on the rear axle.

I don't know about the "mystery hole", my axle is buried too deep right now to check it out.

 

I just went out and checked mine. My D44 axle has the brake fitting just like yours. It also has that hole. It must be a vent hole as there is no other vent on the housing. The D 25 has an "L" shaped vent on the front of the punkin. (opposite side from the U joint)

tommy b

 

I know it’s a different animal, but I just rebuilt a D53 and they have two vent openings through the housing located above each grease fitting. The idea is to fill the bearing at the fittings until it comes out the vents. It also has one threaded hole for a brake tube tee.

 

Guess I'll leave it alone. Thank a lot guys.