yes i currently have a problem with my jeep wrangler yj's 4x4. when i shift it into 4 wheel drive, the 4 wheel drive light comes on, but only one of my tires spins. my back right tire is the only tire that spins in 4 wheel drive. i know i need professional help, but i was just trying to find out as to what's causing this wether its gears, axles, the transfer case, or and combination of things. if anyone has any ideas or information, i would greatly appriciate it.

-baloo

first take a look underneath check to see if linkages are ok etc.

Then go further

My guess would be the vacuum disconnect on the front axle... check the hoses etc... that is the most common failure..

I'm thinking so, too.  On the Dodge disconnect, I think the light was triggered by a switch in the disconnect apparatus, you could say "at the end of the line" - meaning all other links of the chain had to be in place for the light to light (lever in one of th e4WD ranges, transfer case vacuum switch energized and switched appropriately, all vaccum lines intact ane operational, ect.).  On the otehr hand, I think the YJ has the switch in the transfer case, well ahead of the last link. This will allow for some parts to the puzzle to be in place, and the switch appropriately triggering the light "on", but downstream parts may or may not be where they need to be, thus the light "tricked" in to being lit when 4WD is not actually engaged.

I would suggest pulling the dual-circuit vacuum connector off the axle assembly (easy to do from under the hood, passenger side on YJ) and check for a vacuum signal (engine idling, of course) at one port of the rubber thing with two hoses on it.  If it's there, switch the transfer case to 2WD or 4WD (whichever it wasn't in) and see if the other port has a vacuum signal.  One should be on in 2WD, the other in 4WD.  If you have vacuum on one but not the other, you can be pretty sure your "4WD side" is kaput, based on your observation that 4WD is non-operational.  If you find that the vacuum signal does not alternate with transfer case changes (stuck switch), you can just turn the rubber connector (the dual port thingie) Upside down to activate the axle disconnect.  If I had a 1992 YJ with a stuck vacuum switch on the transfer case and were too cheap or lazy to replace it, I may just be tempted to switch this rubber thing right side-up for street driving and upside down for trails.  And that's NOT a very big "if" ,if you get my drift...

Is there any info on how to fix the stuck vaccumm switch on the transfer case?

Scott

I have a 95 yj  

there are vacuum eliminator kits. (engage the front axle with a cable)  

yes I have seen those kits for $200, but I was wondering if there could be a simple thing to check with what I have.  I have traced the vac hoses to the top of the trans case.  The hoses feed into what looks like a coupling or is this an external switch?  On my jeep it is stuck in the locked position.