241c transfer case vent

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Bright Idea

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Scappoos, OR
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Mike
Truck Year
1990
Truck Model
V 2500 Suburbans
Engine Size
5.7
I have a 1990 V2500 suburban, manual transmission, 241c transfer case. The transfer case has an approximately 3/8" diameter vent hose off the top right hand side that runs forward and was terminated near the right exhaust manifold It looks as thought this hose may have continued on at one point in time as there is a barb that looks like it may have had more hose connected. From time to time the existing hose would spew some ATF on the manifold and give off a smoke signal.
Two questions:
Where should this vent terminate ?

What condition would cause it to push enough fluid through the hose to cause this ?
The fluid level is normal ( up to the bottom of the fill opening)

Thanks in advance for your replies
 

Doppleganger

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I have a 208C with about a 2-3" vent hose that ends in a vent cap - like the differentials have - on top of the case.
 

skysurfer

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John
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1989 Suburban
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V2500
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5.7/TH400/NP241C
I have the 241c. That vent hose crosses over on top of the trans to the driver’s side and and terminates at a small round bracket mounted to the forward/top of the bell housing. Looks to be mounted at about the 11 o’clock position. It has the vent gizmo that Dopp referred to. Tried to take a pic but couldn’t get one that was clear enough to show any detail.
 

Jawzjeep

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Joshua
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1991
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Suburban
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Best pic I can get. Its a 91 with an auto though
You must be registered for see images attach
 

bad_idea

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Elizabeth City, NC
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Ben
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1990
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V1500
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6.2L Diesel
Fluid pushing out of the vent is not normal. ATF pushing out onto the exhaust manifold is a fire waiting to happen. I would relocate the vent to an area where the fluid will not contact hot components. My jeep has them on the firewall on the other side of the brake booster (away from the engine). Should be as simple as a new piece of hose and a couple adel clamps. As far as the barb on the end, I believe your vent is missing the cap. Go to any junkyard and pull the vent caps off of a jeep, any jeep.

As far as the reason for the fluid spewing out - I found this thread over on Pirate:

https://www.pirate4x4.com/threads/np241-puking-fluid-out-vent.570567/page-2

Some interesting information in there. Several theories, some common causes, and even a GM Recall that may need to be addressed. The easiest answer I saw was to install a catch can on the firewall to capture the fluid and drain back to the case.
 

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