I have a 92 f150 4x4. My transfer case ate itself so i purchased a used replacment from a reputable 4x4 shop. They opened it up and checked everything out before selling it to me. The issue i am having is the hole for the vent tube should be fine threaded but someone has tapped the hole for what looks to be a 3/8 coarse threaded bolt. So now i am not sure how to vent this thing. There is however a second fill plug (mark fill for pto only) on the front just to the left (driver side) of the normal vent and shift sensor toward the top of the transfer case. Does anyone know what this is and if I can use this location to vent it or can I just run the transfer case with out the vent. This truck is just my project and won't be leaving this area for higher or lower elevations, so theoretically I should not need the vent. Can someone either support or veto my theory so I don't shell another transfer case. Thanks for any input.

 

i personally would find a brass pipe thread nipple that will start in the hole and crank it carfully into the hole till it stops and put a hose on it and tie it to the frame

 

Thanks for the quick reply. I will see what I can come up with at work Monday and then try that with some rtv to back it up in case of leaks unless someone has a better idea.

 

the brass is softer than the steel transfer case hole or is it aluminum? if steel it will cut its own threads and should seal just fine alone

 

its an aluminum case. do you think it will still work. Or have you ever seen that other fill plug i mentioned on the front.

 

well the harder metal will cut new threads into the softer metal so it should work. just not sure which is softer aluminum or the brass

 

I think I will just get a 1/8" NPT tap for the hole. Now since it is soft aluminum will the shavings hurt the transfer case. If so how to keep them out shy of taking the whole case back off and busting the case in half?

 

i would run it for a day or so to wash shavings down to the bottom and change fluid

 

hold a vacuum cleaner hose next to where you are drilling, and catch everything. even aluminum shavings can ruin a bearing. your need a vent, to allow expansion/ contraction.

 

Well so far so good. There is a second fill hole on the front of the case about 1" lower and 3" toward the driver side of the truck that I used for the vent. I will probably have to get a longer hose so I can run it under the shift linkage and away from the front driveshaft. Other than that I will just keep an eye on the fluid level for a while to make sure there are no issues. Thanks for the help.

 

didnt mean to post anything