87 YJ Laredo / 258 cu

It seems to have a bit of bump steer ..... not real bad but none the
less there is a bit of a bump in the steering wheel when I turn
corners. I have inspected the vac lines and they "appear" ok but I
suspect that maybe it was caused by a 1" body lift that I did , but
then again I did notice it just before I did the lift. I plan today to
pull the cover and cycle it in and out of 4WD and watch the fork it
might be sticking, I also have a vac test guage and I plan to check
the vac signal to each side of the diaphram.

You didn't say what year or model, there are some differences.
Pressure switch on the firewall sorta indicates '87 to '90 YJ
Wrangler.

First off, don't worry about the front axle being continuouisly
engaged, all of the TJ's ('97 and later) run that way all the time.

The shift motor is vac pulled each way, in and out. The 4wd
pressure switch and the 4wd light are quite reliable, if the
light works and responds, things are usually all right in the
axle. In fact, the light will not go out until the axle disengages.

The really shaky part of all this is the vac lines and the switch
on the transfer case. ($35 and $15 respectively)

So if all that works, I have to ask what makes you think it is
locked in 4wd? The only thing that can be broken and give you
this particular set of symptoms is the shift fork inside the
shift motor. 4 bolts and you can inspect it.

I was posting as Jeepers and just realized that someone else posts
here using the same name ( or someone else use to use that name) so
you will notice I changed my nick a bit.

Anyways 2 days ago I had my vehicle in 4WD and today I went to work
and noticed that the front axles are locked in 4wd. The indicator
light does not indicate that I'm in 4WD and responds to me shifting in
and out of 4WD. From what I have read when I shift to 4WD the transfer
case of course shifts the gears and via vacuum it trips a pressure
switch to energize the indicator light.....this all seems to be in
order. Also I understand it also applys or removes vacuum on the axle
shift motor and engages / disengages the front axles.

So from this I guess I can assume one of the following:

1:) I have a bad vacuum line
2:) The shift motor diaphram is damaged
3:) The shift linkage from the shift motor is damaged / jammed

Is there an easy way to manually disengage this until I get time after
NewYears to really look at the problem.

Also does it apply vacuum to engage the front axles or remove vacuum?