The vent tube for an auto trans comes off the trans at the rear left side of the trans, follow the left side of the trans upward, and is attached to a bracket on the top of the trans at the shift selector bracket.
Rear axle goes to the left side, and up to the frame.
Front axle goes to the right side, and is attached to the right of the radiator to the radiator support.
Transfer case???? Do not see any mention of this in the service manual, and crawling under our hummers in the rear, due to the shield I can't see the routing. Has to be one.
f5fstop
This post is from 8-2-2005 in the forum by fstop answering a question I had.
I ended up using a marine clamp and 18 inches of fuel line to raise my transmission vent. I'm not sure if they changed it after '06
Hummer Guy/Fstop/Builder Help?
HummerJim