Engine/Transmission (1998.5 - 2002) Front Diff Vent Tube

[Hahn007]

Just wondering if this has happened to anybody else.



After driving in 4X4 at freeway speed I noticed gear oil on the passengers side inner fender well and the two arms that attach the front drive axle to the frame. It appears to have come from the front diff vent tube that attaches to the inner fenderwell just below/behind the stock air box.



I can't imagine the oil expanding enough to pour out of this tube. It would have to increase in volume enough to completely fill the two axle tubes before it could flow up the vent tube. I am thinking it was more like a heavy vapor due to heat in the diff housing. Thing is I don't think the rear diff does this.

 

[GarrettPetersen]

Ive had this happen to me before when I was usein 4wd almost all day long. Looked like foamy oil residue to me

 

[nps]

Had it happen to me twice. Both times after having parked with the pass side low overnight, followed by an extended high speed run on the highway. Was in 2wd though, not 4x4.



The theory is that the diff fluid seeps into the CAD housing. Then pressure buildup from the heat of HW driving forces a small amount out the tube. Doesn't take much to look like a big mess.



Make sure the small plastic vent cap and the end of the hose (under the airbox) is clear and not causing pressure to buildup, else you may blow the axle seals.



Since changing my diff fluid to Redline Shockproof Heavy, I haven't had any reoccurance.

 

[tractorface]

I had the same problem, It was caused by parking passenger side downhill. Overflowed for days and made a huge mess. I echo NPS's statements exactly except I never switched luricants. You have nothing to worry about except a mess Just realize it may go on for days.