This week I noticed my 1988 stock Samurai producing a "chirping" or "squeaking" noise.  It seems to be coming from underneath the vehicle, rather than from the engine compartment.  The sound varies in intensity.  It is most noticeable at higher speeds.  When I let off of the gas at high speed (without pressing the clutch pedal) it is significantly louder.

Also, yesterday the vehicle began to shudder as I started driving from a parked position.  It did this momentarily, then ceased.  After a stop at a light the shudder did not happen again.  On the way home from work the same thing happened right after I started the vehicle up, but did not happen again.  It seems to only occur after the truck has been parked for some time. 

I stopped by a lube shop and had them check the fluid in the transmission, transfer case, and both differentials.  They were all full of clean fluid. 

Any ideas?

Thanks for your time!

The shuddering would worry me most. I would look closely at the shafts and linkage between the transfer case and front tires.

Does it do the same thing in the various transfer case positions? How about hub locks (on vs off)?

You'd better find out quick because it sounds serious (no pun intended).

So I drove it around a little bit and played with the transfer case.  When the car idles in transmission neutral, nothing happens.  When I shifted the t-case into neutral and let it idle, the truck shook.  I noticed when the t-case is in neutral, the shaft between the transmission and t-case spins.  Since that shaft spinning is correlated with the vibrations, it seems that shaft is the culprit.

Could it be a bad u-joint?  I tried to wiggle the shaft, but couldn't get much leverage, and didn't notice any movement.  If not a u-joint, then what else could be wrong with the shaft?

Thanks

sounds like u-joint to me in drive line

It sounds like the ujoint between the tranny & TC.  Or, you could have some bearing going in the TC.  Either way, dropping the TC would be first step.  Then check the U-joint, and turn TC over by hand to see if it is rough.