I drive a 1998 jeep cherokee xj with a 3.5 or 4 inch lift. When I am stopped and I give it gas to go, there is a shaking and a popping that I feel coming from under the jeep. The shaking and popping is louder and more violent the more gas i give it coming out of a stop, and it is especially worse when coming out of a stop going up a hill. Any suggestions to what it could be?

Driveline vibrations? Did you do any form of a transfer case drop? SYE?

I do not believe I have a transfer case drop, but I did have a driveshaft replaced a few months ago due to the stock one being too short. Not sure if that effected anything.

check u-joints poping and shaking while under load is different than vibration...more info needed..when was the lift done?

well bad U joints could be your problem, but that can be caused by bad driveline angle. I would install an SYE and replace u joints

def. sounds driveshaft related. got any mechanic type friends who could take a quick look ?

Im getting it checked out this evening.

The rear driveshaft is most likely binding and that the popping noise. You most likely need a sye or a hack and tap. what t-case do you have? The 242j is longer than the 231j so it makes the drive line angles worse. Sye for a 242j is about double the price than a 231j. Put it on jack stands and run it in 2wd and look for run out in the drive shaft. With a stock drive shaft you want to match your pinion angle with the out put on the t-case with a sye you want your pinion angle to be within 1 to2 degrees down of the drive shaft angle.

Sounds like you need an SYE and some shims for the differential. SYE's can be bought for as little as $150 and some even cheaper on sale for a NP231, paid $99 for one last year on a special sale a RR.