Front Diff. spitting fluid out?

[Burn Down]

My friends 06' LBZ is spitting gear oil out the front diff breather (bad enough to coat the inner fender skirt) when he pulls his enclosed trailer... He is running Mobil syn. 75-90 filling it to the bottom of the check/fill plug. The breather tube is hooked up to the fender skirt. The roads have been super icy this year, so he has been running 4x4 to the mountains, 175 miles @ 55-70 mph.

My truck has never done this but I don't run it in four wheel drive for that long. Anyone else have that problem?

 

[OregonDMAX]

That's really strange I leave mine in 4x4 all the time even at highway speeds on the way to work (on a ski mtn) also use 75w/90

 

[AKlowriderZ71]

This happens when the 'pendulum' on the front diff ventilator isn't hanging down like it's supposed to. If it sticks at the wrong angle inside the diff, the spinning gears push the gear oil straight up into it, and out the hose. GM had a TSB about this years and years ago.

We used to drill the 'pendulum' horizontally, and push a heavy cotter pin thru. Spread the pin just enough that it can't fall out. The weight will keep it hanging down where it needs to be.

 

[Hot COCOAL]

My AWD TBSS does this when I go over 100-110mph
But I overfilled the diff just a tad

I've owned several and I've never had a Silvy do it...
Sounds like there is some excessive internal pressure in the diff for some reason?

 

[Hot COCOAL]

This happens when the 'pendulum' on the front diff ventilator isn't hanging down like it's supposed to. If it sticks at the wrong angle inside the diff, the spinning gears push the gear oil straight up into it, and out the hose. GM had a TSB about this years and years ago.

We used to drill the 'pendulum' horizontally, and push a heavy cotter pin thru. Spread the pin just enough that it can't fall out. The weight will keep it hanging down where it needs to be.

Great info!

 

[Burn Down]

This happens when the 'pendulum' on the front diff ventilator isn't hanging down like it's supposed to. If it sticks at the wrong angle inside the diff, the spinning gears push the gear oil straight up into it, and out the hose. GM had a TSB about this years and years ago.

We used to drill the 'pendulum' horizontally, and push a heavy cotter pin thru. Spread the pin just enough that it can't fall out. The weight will keep it hanging down where it needs to be.

How does one go about getting to this "pendulum"?

 

[DetailsUnlimited]

Mine spits fluid as well. Has for yrs

 

[AKlowriderZ71]

How does one go about getting to this "pendulum"?

Pop the hose off, unscrew the ventilator. It's hanging on the back.

 

[Burn Down]

Dude, you rock! Thanks.