Rear Axle Vent Question

[KAPOW]

Sorry for the post without a photo, I will add it this evening if it's needed.

My question is regarding the rear axle vent line. When laying under the Jeep installing new shocks I noticed that the vent line to the rear axle is not connected. The odd part is there is a factory-type plug with a crimp-style ring at the end of the tube. I chased the vent tube routing and found that it ends right behind the gas cap. The vent line at the top does have the plastic vent fitting.

My initial thought is to just cut the cap off and install the vent tubing back to the fitting on the axle. But why was it capped?

Lastly, does the vent line require any type of clamp to secure it to the axle or just attach it and let it ride?

 

[jjvw]

What was capped, the barbed fitting on the axle?

 

[Jerry Bransford]

Sorry for the post without a photo, I will add it this evening if it's needed.

My question is regarding the rear axle vent line. When laying under the Jeep installing new shocks I noticed that the vent line to the rear axle is not connected. The odd part is there is a factory-type plug with a crimp-style ring at the end of the tube. I chased the vent tube routing and found that it ends right behind the gas cap. The vent line at the top does have the plastic vent fitting.

My initial thought is to just cut the cap off and install the vent tubing back to the fitting on the axle. But why was it capped?

Lastly, does the vent line require any type of clamp to secure it to the axle or just attach it and let it ride?

The vent hose end with the plastic cap on it next to the gas filler cap needs to stay there, the other end of the rubber hose with no fitting is what slides over the air vent nipple on top of the axle tube. You may need to trim a little if it's split. You can use a zip-tie or a small hose clamp if it's not seated firmly enough to make you happy.

 

[KAPOW]

What was capped, the barbed fitting on the axle?

No, the tube end itself was capped. That's why it was so strange.

 

[Jerry Bransford]

No, the tube end itself was capped. That's why it was so strange.

Very strange indeed.

 

[BlueC]

My initial thought is to just cut the cap off and install the vent tubing back to the fitting on the axle. But why was it capped?

Does the "cap" look like this? If so, that is a vent.

 

[Jerry Bransford]

Does the "cap" look like this? If so, that is a vent.

View attachment 495801

View attachment 495802

View attachment 495803

X2, that's the end that is supposed to be attached up by the gas cap filler assembly.

 

[KAPOW]

Does the "cap" look like this? If so, that is a vent.

View attachment 495801

View attachment 495802

View attachment 495803

No, I have the vent installed behind the gas filler where it should be. This is at the end of the rubber tubing within inches of the vent port off the axle.

I'll take some photos tonight when I get home and attach the tubing.

Just a mystery as to why someone would cap it.

 

[Jerry Bransford]

Just a mystery as to why someone would cap it.

Remove the cap and be done with it.

 

[macleanflood]

Someone probably didn't know what they were doing...hell for all we know they thought it would fix an evap leak.

Pull the plug off and reinstall it on the axle. Zip ties and cable clamps work good...I also like constant tension clamps.

You also want to verify that vent into the axle isn't plugged...I'd get a shop vac and pick and make sure it's not plugged up with something.

Then I'd drop the diff cover and clean everything out... depending on your level of sanitary you might want to pull the carrier and axles and swab out the tubes. I doubt that's necessary (unless you like mudding, deep puddles and fording rivers.)

Fresh fluid is a good idea for an axle with an exposed vent.

-Mac

 

[KAPOW]

I'm a tad OCD so my plan was to order new diff cover gaskets and remove, clean and reinstall this weekend.

 

[jjvw]

....

Just a mystery as to why someone would cap it.

People do weird things when they don't understand what is happening.

 

[macleanflood]

I'm a tad OCD so my plan was to order new diff cover gaskets and remove, clean and reinstall this weekend.

Gaskets aren't needed...lot of us just use RTV. Lube Locker makes a reusable gasket...I like mine...some folks who like hitting rocks hard report mixed results.

But... your Jeep and your rules!

-Mac

 

[KAPOW]

Gaskets aren't needed...lot of us just use RTV.

Ahh, just the red RTV?

Someone has gotten into the rear diff before, looks like a 5 y/o art project.

 

[macleanflood]

Ahh, just the red RTV?

Someone has gotten into the rear diff before, looks like a 5 y/o art project.

My preference is Right Stuff or high torque grey...not that it's high torque. Honestly you could use anything. Advantage to Right Stuff is 1 minute able to fill and 90 minutes to cure.

-Mac

 

[KAPOW]

My preference is Right Stuff or high torque grey...not that it's high torque. Honestly you could use anything. Advantage to Right Stuff is 1 minute able to fill and 90 minutes to cure.

-Mac

Great, appreciate it Mac!

 

[JMT]

My preference is Right Stuff or high torque grey...not that it's high torque. Honestly you could use anything. Advantage to Right Stuff is 1 minute able to fill and 90 minutes to cure.

-Mac

Great, appreciate it Mac!

The Right Stuff 1-Minute Gasket Maker "all the way." Love that stuff. Never failed me on thermostats, diffs, TCases, etc...

 

[KAPOW]

The Right Stuff 1-Minute Gasket Maker "all the way." Love that stuff. Never failed me on thermostats, diffs, TCases, etc...

Perfect, will grab some on my way home.

 

[KAPOW]

Great, appreciate it Mac!

Do any of you have a preferred axle fluid?

 

[Jerry Bransford]

Nearly any GL5 is fine. Do you know if your rear axle has the factory Tracloc limited slip differential? If you do just make sure the back of the gear lube bottle says something like 'Compatible with limited slip differentials' which says it has the required friction modifier. Most GL5 lubes have that. Some aftermarket lockers/LSDs specifically advise not to run a friction modifier.

The exact viscosity is not critical. For most casual driving a lower viscosity like 75w-90 or 80W-90 is fine. For towing or more extreme duty something a little heavier like an 85W-140 would be fine.