12 Bolt Vent ?

[54blackhornet]

Do all 12 bolt rear ends have a vent in them, or just 4x4 applications ? I pulled this photo off the board as an example. After cleaning up all the sludge off mine all I have is a hole in top of housing where the fitting goes ? I hope a lot of crap did not get inside ?

[CUSTOM/10]

Yes all should have a vent. The end of the tube should have a plastic vent on it and be tucked up in the frame rail to help protect it from getting water & dirt in it. It wouldn't be a bad idea to remove your rear-end cover and take a look inside for and signs of dirt or water.

As the rear end heats up with use the oil, air expands then contracts as it cools. If this vent line isn't on then it can suck water & dirt in as it cools.

Gary

[54blackhornet]

Thanks I am expecting the worst ? The truck was beat on bad by PO and I am considering swapping out to different rearend completly.

[GASoline71]

Pull the cover and check?

Gary

[67c10rustbuket]

They (fitting on diff) usually just get plugged up and cause leaks elsewhere. Here is a pic of mine and a link to the vent. Dorman part num 14689, Probably buy them anywhere but I added it to my cart while shopping on summit racing. Never mind the blue zip tie. It's temporary.

http://m.summitracing.com/parts/rnb-14689

[54blackhornet]

You are spot on ! The right rear axel seal was leaking real bad, saturated the drums with oil. Thanks for the lead on the filter, any one have a photo of what screws into the housing that hose attaches to ?

[67c10rustbuket]

It's a 5/16 OD beaded tube, press in. If yours is missing I would probably tap it to 1/8 npt and use a 1/8 npt x 5/16 barb fitting from a hardware store. Or you can get fancy stainless vent and screw it in the diff but I like the hose to keep the vent up out of the elements.


Getting kinda dusty in the garage...

[54blackhornet]

Thanks to all for your help.....

[Rich72C10]

I have this small leak under my pumpkin for some time now and about two years ago I had the rear end oil changed, which I thought would fix it since it would get re-sealed. After I got it back it still leaked the same, I complained and they changed the seal again. Still the same small leak - auto shop said take it to a rear end shop :-/

Fast forward to today, I found about the vent tube in this (and other) threads. I have the tube and it was plugged (had some kind of a critter's cocoon plugging it up). I pulled it off shoved some stuff wire inside and washed it out.

Next up is to install one of those Dorman 14689 vents, that should keep the critters out and getting plugged up again. On that note, I ordered it from Amazon and they are 50% off, total shipping (next day Prime) $3.02!

It isn't a constant leak just sitting in the garage, only seems to leak after it has been driven and parked again in the garage. Just enough so the bottom end of the pumpkin stays wet and a few drops on my garage floor. Anyways, hope this helps / solves the leak without having to replace the seal again...

[NGN]

Interesting info here I'll be checking mine out. I have no leaks but easy maintenance for a clear conscience. Thanks

[Rich72C10]

Cleaning out vent line did no solve the leak.

Though this time I had cleaned all around the cover / pumpkin and the leak is coming from a indent on the right back side. It almost looks like it is some kind of a plug that started to weep. I forgot to take a photo before trying a fix.

So I cleaned the area real good and put a good dab of JB Weld around it. The center of my red circle is where it seemed to be weeping. So I'll let that dry really good for a day or two and to see if I was right.

Edit:
2nd photo attached I found in this thread. I assume this is what I have put JB Weld on..

[Ironangel]

Those are factory plug welds that weld the center section to the tubes. Most of those welds are full of porosity and many do weep a little gear lube. When I rebuild an axle I fill those holes with weld from my MIG gun. That only works on axles that have been disassembled and cleaned because they'll just bubble up from the oil trapped in the porosity. Mix some JB Weld and after spraying each weld with brake clean and drying it with either a propane or oxy-acetylene torch. Then fill those plug welds with JB-Weld to seal them...Use a popsicle stick to fill them and then use a piece of duct tape to hold the epoxy in the weld hole until it sets up...

[Rich72C10]

The photo on the left is mine after cleaning with brake cleaner and using JB-Weld - I used a wooden side of a cotton cleaning stick.

[Rich72C10]

Attempt two, after still getting a bit of a leak. This time I scrapped, sanded, cleaned all around and exposed the plug fully. Then put JB-Weld back on - hope this does the job.

Edit:
Looks like I got it fixed after my morning drive & taking my daughter to work this morning. What a annoying issue to have! After talking to my brother, apparently he has some kind of special jig for rear ends that is used for modify (shorten?) and allows you to re-seal these plugs. Something about using nickel rods or some such. Anyways, I am also glad I was forced to check the vent because that thing was plugged and fixed to.