Another 4WD Question
 

Just put a RE 3.5 lift on my 89 XJ. I have learned LOTS from this forum, and I'm grateful for this forum. You guys have been a huge help over the past few months while working on this thing. I'll post some pics when I get a few more things done.

One of my mods was to replace the non working front axle vacuum shift with a cable to manually lock the axle from inside. So, driving in 4WH Saturday on a fairly steep gravel road, passed my road, stopped and put in reverse. All that happened was the rear wheel spun and both the new 31" BFG's did nothing but sit there looking nice. I tried switching from 4H to 2W to 4L then 4H and still no help from the front wheels. I locked the front axle and then I had 4wd.

What would cause 4wd to not work till I locked the front axle. Shouldn't I at least have one front wheel turn with the axle unlocked?

no, unless you have a full time locker. If you have an open diff (which you do, from your description) it will just turn inside the diff housing. An open differential sends power to the wheel with the least traction, in your case the axle where it is disconnected.

AAHHH! That makes sense now. Thanks!