Axle breather holes

[PaulS]

In the picture:


The red circle is around where the grease Zerk goes.  (Lighter colour because the Zerk is removed and I have a light shining through it.)

Question:  Is the hole circled in blue the breather hole?  If so, should I clean (or drill) it out?  I am presuming I should.

Second question:  I've read that there are breather holes on the axle tube further inboard.  Do these need to be cleaned out?  If so, how the heck do I find them under a coat of paint?

Thanks,

-Paul

[1955CJ-5]

If I remember right only the rear axle has breather holes, as the front axle has a breather in the diff cover..

you should clear the breather holes. They should not need to be drilled but a drill turned by hand would be a good tool...though the grease may be pretty hard.

Here are the hole locations on the rear axle. The left end is similar to the right. The hole in the tube is just inboard of the left spring "u" bolt, as you look at it from the rear...on my axle it is 8 3/4" from the lip where the tube enters the differential casting.

[Carls_jeep]

The hole in the bearing area is for grease to bleed out of when you put grease in the Zerk. The hole in the axle housing inboard of the spring U bolt is for the axle to breath. The problem with that hole is when your hot rear axle goes into cold water the water gets sucked into your rear end then you have water in the oil.

If you plan to drive through water you need to plug those holes and braze a fitting in the rear cover and run a hose from that up through the floor and clamp it to the body with a breather on the end.

You need to to the same with the front axle. Just remove the breather, put an elbo fitting in and run a hose up to where the batter box is and clamp it to the side with a breather on the hose end.

If you don't drive through water past half way up the tires you needn't bother.

[johnrb3b]

What Carl said.
The two grease relief holes next to the bearings are so you don't get carried away with your grease gun, pump in way too much lube and force it past the seals into your brakes.

The breather hole closer to the center of the axle is just for air pressure equalization and it can take in water. You can put a right angle fitting into that little hole and run tubing down the axle to the differential and carry it up along with the flex brake line to the tub and on up as high as you want.

Having done that, the only axle issue in water crossing is just that you got your brakes wet and they won't work too well until they dry out.

[PaulS]

I can't find the holes in the axle tubes.  The ones at the ends were pretty obvious, once I knew to look for them, but the others just aren't. Even looking from the inside...

Oh well.  If they're hiding, they're sealed up with paint.  I'll put a breather on the differential and be done with it.

-Paul

[Bob W]

I can't find the holes in the axle tubes.� The ones at the ends were pretty obvious, once I knew to look for them, but the others just aren't. Even looking from the inside...

Oh well.� If they're hiding, they're sealed up with paint.� I'll put a breather on the differential and be done with it.

-Paul

There is only one differential breather hole on the rear of the driver's side axle tube. See the Willys info below and the photos above....

On the M-38 they eliminated the axle tube vent hole and put a breather in the rear cover. There were problems with gear lube being forced out the breather when driving, the gear lube was being forced out the vent by the direction the ring gear slings it. This isn't a problem on the front axle since it's slinging the oil down. Their solution was a baffle on the inside of the rear cover to deflect the gear lube away from the vent. Most more modern rear axle vents are composed of a fitting in the top of the axle tube with a rubber hose that goes up to the frame somewhere.

[Bob W]

Just another bit of info...

There was a tendency for Army mechanics to pump too much grease into the M-38 rear wheel bearing grease fittings. The extra grease got into the brakes, so they issued a "bulletin" where the two grease fittings were to be replaced with plugs.

[PaulS]

Thanks Bob!  I found the hole.  I had been looking on the top surface, not the rear.

-Paul