front axle Q's

i did a search looking for these 2 questions and came up with nothing (may have been barking up wrong tree but i still need help)

i will start with
i recently lifted my 1990 XJ 4x4 auto i lifted it 3"s and today i went to shift into 4x4 and it would not engage so i crawled under front and pluged in a yello plastic line into the axle that was disconnected and then i looked under the hood and i found a blue line disconnected Can someone please tell me what this connects to and how to keep these lines from being disconnected

what is the proper way to shift into 4x4 also??


thank you for the help

I think this might not help cuz I have a '91 but had similar probs after install of my 3 in lift too. I don't have a yellow or blue line or can sorry there. But the linkage got unhooked when I went to try the 4wd. Just needed to pop the rod back in and add a new copper or whatever clip it was on the back at a trans shop. Afterwards I threw in a t-case drop and haven't had a prob. As far as proper shifting, the driver's side visor should have info on the back or your owner's manual. I can only say I throw mine in 4hi up to 60mph, book says 55mph and I stop and put trans in neutral and pull in 4lo and only take that up to like 20mph at most. Same for backing out from these, make sure u stop to go back to 4hi or 2hi or slow down to go from 4hi back into 2hi. Mine has a solid clunk and sometimes depending on the rpm won't shift properly so don't force anything, just back off some more or try it after moving a few feet. Hope this helps, good luck!

The blue line is the vent to atmosphere, and should remain open.

titan has the idea on shifting.

Ideally, you can go back and forth from 4 hi to 2 hi without a care, but if tire wear or loading is a bit uneven you should at least back off on the accelerator, and may even have to stop or back up to disengage it. You should never engage it while any wheels are spinning, but otherwise you can just engage at will. It will be unhappy about disengaging if it's under load, so let off on the gas to avoid a delayed clunk. This is more or less the same whether or not you have an axle disconnect, because neither the disco nor the transfer case likes to disengage under load (unless, of course, you have a vacuum leak, in which case it will randomly disconnect under load. I never figured out why it is so slippery when it's broken and so sticky when it isn't!)

Extra noise or a refusal to come out of 4 high is a cue that you should check the pressure and condition of your tires. It may be time to rotate to equalize wear.

Do you have a disconnect front axle? Those yellow and blue lines sound like vacuum lines for the shift fork that would lock a front disco axle into 4x4.