Seems every time I change the oil and check my case and differentials my transfer case always seems to need ATF. My case is dry front and back so I have no idea where this is going. Possibly a vacuum line? Any ideas? Thanks!

 

There are no vacuum lines on your transfer case. You sure your not talking your tranny?

 

I call it the transfer case-the one that engages the driveshaft to the front differential. I'm wanting to replace my vacuum lines also and trying to figure out all the lines running to the transmission also.

 

If it's not leaking to the outside some where then the only place it can go is into your transmission. General if there is a leak in the gasket to the trans it will push fluid into the tcase from the trans not the other way around. Beyond that there are only really three places for it to leak the rear output the front output or where the two halves is the cases meet. How are you checking the level?

 

3-button or 4-button 4wd?

The 3-button setup does have vacuum lines attached to the vacuum switch on the side of the transfer case. Inside the switch are two o-rings. If the inner o-ring were to fail, it would allow vacuum pressure to pull ATF out of the t-case and into the vacuum system making a royal mess.

 

It's the 3 button setup but I don't notice any fluid in the vacuum lines. I check the transfer case by unscrewing middle plug and sticking a zip tie in. When I worked at a COOP I was taught it should run out the middle plug. I'm thinking of replacing all the vacuum lines. I notice sometimes the cruise control doesn't work. I pulled the check valve and moved some lines and now it works so something is going on. Last winter when it was really cold the 4x4 didn't want to kick in-so I put it in neutral and hit 4-Lo which finally made it pull in, then I switched to Hi. I tried once engaging while on the move and it made a grinding noise like it was having trouble locking in. Why such an elaborate setup when they could have simply kept a manual gear lever on the floor....yea I know-repair money and for people who have no clue how to do that.