Front differential vent tube overflowing?...

Mahukaawe · 11-07-2009, 04:43 PM

I just noticed a thin coat of oil underneath the van. It looks like it was dripping down and spraying back while driving for a while. It's not bad, just a thin coat and doesnt seem to be dripping at all while parked.
We traced it forward and up to where it seems to have originated at the top of the front diff vent tube which is all the way up on top by driver side firewall when the hood is open.
It is gear oil not engine oil and its not coming from the steering box.
Has anyone else seen this happen and could it be a result of an overfill?
Also, if I am driving in 2wd how would it overflow? Isnt the front diff gears just sitting in 2wd?
Is there something else I'm missing or should check?
I guess I could open the plug in the diff to see if it is full too.

Ed in Montana · 11-07-2009, 04:53 PM

I'm not sure this is exactly what is happening in your situation, but I blew half the oil out of the front differential (from the top of the front pumpkin) by driving in 4WD on paved roads for about 40 miles. The front diff needs the wheels to slip on gravel or dirt surfaces, and overheats when driven on dry paved roads.

If the van is really in 2WD for the rear wheels with your front hubs unlocked your front diff should be doing nothing, and certainly not spewing oil.

LeadDoggy · 11-08-2009, 09:24 AM

do you cross alot of rivers?

Mahukaawe · 11-08-2009, 10:56 AM

No LeadDoggy, I havent had the opportunity to cross any rivers yet. Looking forward to trying one day though. The van is new and it has been in 4wd only once since picking it up.
I'm wondering if that is when the fluid leaked now since it doesnt seem to be leaking while in 2wd or parked.

scatter · 11-08-2009, 04:46 PM

Well, if your transfer case for the front is in neutral and the hubs unlocked, nothing in the front end should be spinning. If either one of the above is engaged and you're driving at high speed, you'll probably puke some fluid out of the breather.
I wouldn't know this from personal experiance of course....

Mahukaawe · 11-08-2009, 05:02 PM

Gee Scatter as it turns out the "owner" of our van has just noticed that I, that is "someone" forgot to unlock the hubs......
So I guess I'll just pretend this thread never happened.

Greggd · 11-08-2009, 06:57 PM

Like Scatter I personally have never forgot to disengage my Hubs , but that will cause the very thing that you described . You should periodically engage / lock your hubs while running around town for the purpose of lubrication , just don't run at higher speeds for prolonged periods .
Greggde