I think so its just. A vacuum line coming from the 4×4 that has a round hard plastic piece yeah it could be a valve

 

its a vent

 

http://www.pirate4x4.com/forum/showt...php?p=12767839

 

mine had this prob what i did was started xj shifted in 4x4 and pulled the line off at axle checked for vacuum, you can feel the suction with finger i had none then i pulled the connector on tc and vacuum was present, so i replaced the switch on tc problem fixed. if you dont get vacuum at either follow the line untill you find the issue

 

Alright thanks for all the help. I'm gonna get Working on it and see wat I can do. Ill post again afterwards thanks again

 

Know I haven't posted in awhile but I did find my problem. My vac lines ended up all being broken above the tranny. But couldn't afford to fix right away had to replace other parts on the xj first. So last week finally ordered the psl920 posi lok engagement system . Received it Friday installed it Saturday. Works great now. Luckily I bought my xj from the original owner and they had never used the 4x4 so my shift fork looked new as hell. So didn't have to replace it. I picked up the psl920 for 175.99 free shipping oh yeah!!!