What goes here?

[Woodsplinter]

Interesting. So it's something similar to the "breather" found on the axles? The little spring loaded cap that farts air out.....

I can't imagine it would last long due to grease catching everything and just hanging onto it. Wouldn't take long to clog up IMHO.

No, not the same breather. Check out the link earlier in the thread for a pic.

 

[nchittendon]

I know its not the same, I said similar to what's in the axle. One way pressure relief. And I did see the pic earlier in the thread, but it doesn't show the inner workings.

 

[rustystud]

I know its not the same, I said similar to what's in the axle. One way pressure relief. And I did see the pic earlier in the thread, but it doesn't show the inner workings.

This relief doesn't allow anything back in unlike the axle breather. It's a one-way only relief valve used when there is too much grease in the slip yoke.

 

[welldigger]

This relief doesn't allow anything back in unlike the axle breather. It's a one-way only relief valve used when there is too much grease in the slip yoke.

I'd rather just stick a pipe plug in there with a small hole drilled in it.

 

[Jeepsinker]

I'd just leave it open unless you plan on mud bogging.

 

[nchittendon]

This relief doesn't allow anything back in unlike the axle breather. It's a one-way only relief valve used when there is too much grease in the slip yoke.

This would be where my confusion stems from.......The axle breather lets air back in as well!? I was under the understanding that the axle breather was one way only......

 

[nchittendon]

This is the dude I'm talking about.

 

[RAYZER]

The axle breather style cap doesn't let air back in, it's one way.

 

[Woodsplinter]

I'd just leave it open unless you plan on mud bogging.

I would be okay with that except that the grease shield around that open end was coated with about 1/2" of grease. The end of the propeller shaft was nearly empty of grease, although it was next to the grease zerk. The splines were, however coated with plenty of grease. If both sections of the shaft are compressed as close to each other as possible, there is about a 2" "empty" space inside the tube. The location of the zerk is about 1" from the end of the splined shaft when installed on the truck.

This makes me wonder how the grease gets all the way to the "in-board" end of the splines- if the grease travels towards the transfer case, it will fall into the empty portion of the tube and won't lube anything.

Im sure this is confusing without a pic so I'll post on as soon as I can.

 

[rustystud]

The axle breather style cap doesn't let air back in, it's one way.

My bad. It depends on the style of breather. Some just use a ball and socket, while our trucks use this spring and puck design.

 

[rustystud]

I'd just leave it open unless you plan on mud bogging.

That would allow all kinds of crap to get into the splines. Even if he never goes offroading regular roads are pretty dirty .

 

[jhooah]

If you read through the Army manuals, PMCS (Preventative Maintenence Checks and Services) would call for greasing the joint during it's periodic maintenence. Simple enough, GI wipes the grease fitting clean, squirts in a few pumps on the grease gun until as the old grease emeges out the relief fitting, then (THEN) he wipes away the excess and moves on to the next fitting. This way he doesn't shove the axle shaft backward damaging u-joints by hydraulic pressure, or blow any seals in things like M113 hubs (at one point they switched to oil filled hubs with a viewer window then back to grease)

But if you have been around US Army material, you will find these simple devices employed on many grease point fittings. Nothing new here and I would install one if you can find it, or forgo fording until you do, or water and dirt will enter the shaft end and slowly destroy the joint, etc.
Not that complex. just a zerk relief fitting.
V/R W. Winget

 

[m-35tom]

the axle vent is designed to let air out and other stuff not in. the grease vent is designed to let grease out and other stuff not in. similar but not the same, the grease vent needs to dump a lot of grease quickly in some cases to prevent damage. put what belongs there back in.

 

[Woodsplinter]

the axle vent is designed to let air out and other stuff not in. the grease vent is designed to let grease out and other stuff not in. similar but not the same, the grease vent needs to dump a lot of grease quickly in some cases to prevent damage. put what belongs there back in.

Thanks Tom- Phil is sending me a grease vent which should fit. Nothing was there when I got the truck so it's been a mystery until now. Not being a mechanic, I had no idea such a thing existed.

 

[M35A2-AZ]

Thanks Tom- Phil is sending me a grease vent which should fit. Nothing was there when I got the truck so it's been a mystery until now. Not being a mechanic, I had no idea such a thing existed.

Sounds like you got one on the way. Good deal, good to know what it was called.

 

[Pugsley]

Well I don't thing I will ever be able to look at my diffs the same way again.

 

[Woodsplinter]

I would be okay with that except that the grease shield around that open end was coated with about 1/2" of grease. The end of the propeller shaft was nearly empty of grease, although it was next to the grease zerk. The splines were, however coated with plenty of grease. If both sections of the shaft are compressed as close to each other as possible, there is about a 2" "empty" space inside the tube. The location of the zerk is about 1" from the end of the splined shaft when installed on the truck.

This makes me wonder how the grease gets all the way to the "in-board" end of the splines- if the grease travels towards the transfer case, it will fall into the empty portion of the tube and won't lube anything.

Im sure this is confusing without a pic so I'll post on as soon as I can.

This should give an idea of how everything fits together:
Not sure how the grease gets from the zerk back toward the diff.

 

[Woodsplinter]

This is the relief valve Phil sent me. Screwed in fine with no thread work needed. It's tight, but there is enough room for the valve to pop open completely.

 

[Reaper651]

Well, Now I have another thing to check on my truck.

 

[phil2968]

Wow, what a nice shaft! Clean and painted!