Popping noise when driving. Seems to be coming from the transmission or transfer case. Sounds almost like a metalic pop like something temporarily hung up and then released. It doesn't do it all the time but does tend to do it as I accelerate or go up a hill-anything that may put a bit of an extra load on it. This is a 4wheel drive with low medium and a high range shifter and a standard five speed shift. I had thought it might be from the rear-end or the rear brakes temporarily binding up and releasing but I don't think that is it. I also checked (visualy and by moving) the drive line for play in the U-joints but there is none. Whatever the cause of this it is getting worse. It only used to be occasionaly-now it is happening every time I drive it and usually as described above. One other thing-whatever it is it makes the truck lurch when it pops just as if something is happening in the drive train. The "pop" and "lurch" can be very faint and subtle or it can be very intense usually though it is somewhere inbetween.

don't attempt any more driving get it towed or more damage could /will be done

05 GC, but what drive line, what engine, what transmission, what transfer case. and evne more important where is the 4wd lever set?
does it make noise in all gears, all transfer case MODES????

sure , buy and electronic stethoscope
like this,
http://www.amazon.com/Steelman-97220-EngineEAR-Diagnostic-Listening/dp/B00396FBRY/ref=sr_1_fkmr1_1?ie=UTF8&qid=1414326169&sr=8-1-fkmr1&keywords=automotive+electronic+stethoscope+steelman

you clamp the mike to many drive line parts.
transmission, quite at POP time.
transfercase quite?
then move the MIKE to the suspension parts.
you will find it.

thats a lot cash to spend guessing. the tool works like magic
it will show you (heard) what is making noise.
if it cant find the noise, 99%^ its U-joints, after all i can not
clamp the MIKE to drive/prop shafts. .
but that is a big clue,

have you tried spraying all suspension joints with silicon oil spray.
that would be first. way before parts.
are you in the salt belt????? google that.

Last, what 4wd you have, options?
Quadra-Trac-II NV 247
Quadra-Drive NV247

more testing
if you shift the xfr case to neutral just before a bump does it still make noise?
then repeat that for transmission , neutral.
do the tests off road, or far from other cars, and peds.
repeat the test in 2wd selection,
seen here. (im assuming this is what you have, its unstated)(
http://www.fixkick.com/Jeeps/QT2004.JPG


ps: noise is the most complex problem
it is also very dangerous on cars that only make noise moving.
use a stethoscope. and find this easy an safely.
use real headphones(muffs)
and 2 persons, one drives other listens and barks orders.
win.

If it won't go into gear, sounds like you've run out of transmission fluid. That grinding sound when you turn the shaft by hand, sounds like you've run it for a bit too long without fluid and wore the gears down. Start it up and check the trans fluid with dipstick. If none on stick, put some in it. You may have already ruined the transmission though. But you never know. Try putting fluid in. Might work.(for a while)

inspect for worn components from output of transfer case to front diff input. If everything is tight and solid from those two points, everything else points to being transfercase internals. Make sure your actuator isn't faulty causing a "4x4 to 2x4 shift on/off"

Sounds like gear and chain need to be replaced in transfer case.
The popping and or clicking is the chain trying to climb up over the teeth on the gear in transfer case.

CV Joint went out. since it gets worse when you turn right it is most likely an inside drivers side CV joint or the out side passenger side. The popping sounds was probably the dust boot popping from pressure build up which should make it simple to locate since you just need to identify the boot with a tear in it.

Sounds like you have something broken in the transfer case. Two wheel drive is transmission to rear end. 4x4 mode engages the transfer case, possible broken tooth on a gear, or bad synchronizers

Transfer case would only be if you are in 4 wheel drive. this sounds like a rear end or u joint issues. Get under the truck and grab the drive line, if you are able to turn it more then a 1/4 inch each way bad u joints. If not then check the rear end.

Could be transfer case. or universal joints on the drive shaft. you have two a front drive shaft and a rear drive shaft. If you have access to a lift you could have someone to accelerate the vehicle to 60 while you listen underneath what out for the moving parts.

Possibly you have a leaky or cracked exhaust manifold. After the engine heats the metal expands and creates a larger gap. As the engine speeds up the engine noise overcomes the exhaust leak noise and you don't really notice it much until the vehicle gets in to a hard pull or comes to and idle.