t-case question

I recently purchased a 98 xj and i've noticed about a 30-40 second delay after i shift from 4wd to 2wd. After i engage 2wd the front end stays locked in. I'm not too familiar with this system. Is it vacuum activated ? Electric ? Anybody ????

It,s not vacuum.It,s not electric.
It does take awhile for the gears to un-mesh or un-couple and they will un-couple quicker if they are not under load.
Wayne

First question - NP231 or NP242? How can you tell? Check the shift pattern - if there are two 4HI positions, it's the NP242.

Either way, there are vacuum switches that engage the lights - the transfer case itself is mechanically shifted. There is a vacuum switch, however, and what you check depends on the front axle (which depends on the transfer case...)

If it's the NP231, there's a vacuum actuator on the front axle (long shaft - pax side) that moves the slip collar to tie the inner and outer shafts together. This needs cleaning sometimes, I've just dismounted and worked carburettor cleaner thru it - there are two ports on it, and the light comes on and off when the axle is fully engaged or disengaged.

For the NP231 or 242, there is a vacuum switch on the transfer case itself, but I've not known it to need cleaning.

From what you're describing, I'm almost certain that you have an NP231, and I have the exact same symptoms on my 88.

CAVEAT - I do not recall if the disco front axle was eventually deleted entirely, so check for yourself before you act on this advice! TANSTAAFL/YMMV.

5-90

On later models, the part time light is controlled by a simple switch in the TC.

The front end will stay locked in. There is no disengagement of the axles.

One common cause of reluctance to come out of 4WD is uneven tire diameters. If you haven't rotated your tires and checked the pressure, that might help. If it's really bothersome, you can almost always get it to disengage by stopping and reversing for a moment, but it really shouldn't need that.

It also helps if after you shitf you let off teh accelerator for a few seconds than get back on it.

Thanks for the input. It hasn't caused any grief, but was curious if it was common in other xj's.