Good afternoon,

I've been a lurker for a little while and I enjoy the site.

I apologize in advance if this is in an inappropriate part of the board.

I was wondering if any of you have seen issues with a clogged front different vent tube (breathing tube?).

I was driving on the highway and the front diff seized. Fluid spewed everywhere in engine compartment but dealership said that it was the result of a missing fill cap. The mechanic I took it to, to be repaired, said that there is no way the fluid leaked out, it definitely all came up and in. He is reputable and I trust him entirely.

I know it's probably a freak thing, but have any of you experienced it? Dodge will not honor warranty because of the missing cap. "If you had the cap, there wouldn't be an issue." I'm beginning to think they never even looked under the hood.

Thank you for any advice you all might have.

-B

 

Where does the mechanic think the fluid came out anyways? Because even if the breather clogged, that isn't going to cause the diff to heat up and fail.

 

If the cap was missing it could cause a problem if water was allowed to enter the diff. But what happens when it seized? Did it break the case? Break the shaft? How did the oil bet up the tube and in the engine bay? Doesn't really make sense.
I've never seen it but I have seen digs fail because of mismatched tires front and rear, what year and model truck is this?

 

If the cap was missing the diff would have been tossing oil out of the hole. I assume that he had a typical seizure - bearings ran dry and welded themselves up.

 

If the cap was missing but the vent was stil there it shouldn't toss any fluid out unles it was overfilled. Or are we talking about a missing fill plug? I'm confused, what is a fill cap?

 

I assume he is talking about the plastic fill plug on the cover of the diff.

 

oldjeep - he told me there was a breathing tube / vent tube or something of that nature in which any pressure could escape out of. He showed me the new one he put in and there is a tiny cap on the top of it that opens and closes, i don't really know what to compare it to as an example. he said that it's possible it became pinched or the top part that opens and closes became clogged and pressure had built up. The car was indeed in four wheel drive, on highway, intermittently during the 74mile trip. I was not going above the 4wd speed rating and it was off at the time that it occurred. However for half of the trip, I'd say it was on. It was about a little over a month ago when we got a huge snowstorm in the northeast.

As for causing the Diff to heat up and fail, it's believed that pressure built, blowing out the clog in the vent tube and possibly the fill cap as well, leaving no fluid left in the case, causing it to freeze up.

Largefarva - I hope I was accurate in my original post... by engine bay, do you mean basically the entire area under the hood? because that is where all of the fluid was. it was a serious mess. Nothing entered the actual 'engine' itself. I don't know about the shaft, but I believe that was also damaged. The dealership told me i needed a 'whole front differential replacement.' The case was cracked. The tires are both the same on the front and this is a 2011 with 47k miles. At the time it happened, it seemed like there was smoke behind me (I thought it was salt dust / snow originally) for about ten seconds. It felt as though the car shifted into neutral, I pulled over, as I came to no more than 5MPH on the shoulder, the car's front wheels locked up and I came to a very sudden stop. The wheels were locked and when pulled onto the flatbed, i heard a large snap, presumably unblocking whatever was locking them, allowing them to rotate freely.

oldjeep - one thing I'm not sure about is how the cap could have come off, dodge, along with other mechanics told me that this was *******ly 100% unlikely. My question is -- if this cap was missing from the start of my trip -- would it have lasted 74 miles before causing the diff to fail?

largefarva - as oldjeep said, it is the plastic fill plug (i've been told it is rubber and i've been told it was steel, never plastic). It is about halfway up the diff case. Not to be confused with the drain plug.

let me know if that helps answer your questions. Unfortunately, I'm not so mechanically inclined so I understand my responses might be confusing.

Thanks again for all of your help.

-B

 

if this cap was missing from the start of my trip -- would it have lasted 74 miles before causing the diff to fail?


Definitely. Its not like all the oil would have left the diff in seconds, and it takes some time to heat up the bearings and to push out the oil, especially when there is no load (not in 4wd)

 

Hi oldjeep.

That was what I had thought. When it happened, I researched it extensively and it seems as though that piece could have been missing for a while. I hadn't had 4wd engaged in about a year prior to this time and I don't really do any offroading or anything that would have changed the pitch of the truck that may have caused it to leak out more than if it had been rolling flat.

With that being said, I know a fill cap coming off is nearly impossible / very random but, if it had indeed fallen off long before the trip or during the trip, how would it explain the differential fluid that looked like it had exploded everywhere under the hood? My mechanic showed me where the vent tube comes out and, needless to say, it's right near the windshield washed fluid container (or something like that, maybe power steering, but a driver accessible area for sure).

It's just very perplexing and I was wondering if any of you all had some insight or experience. I've been looking, literally, everywhere and can't find anything regarding it. Between people i speak to, multiple mechanics, websites, etc. no one has a similar issue. I created a website with some keywords about the issue, hopefully if someone is out there googling it, they'll come across it and send me a message.

Again, thanks for your input. I really appreciate it.

-B

 

No idea how it would have exploded out the vent tube unless the diff was full of water. When you aerate water into gear lube it'll foam up like crazy and could shoot out the vent, but it would be fairly obvious just from the color of the mess that it was full of water.