2000 cherokee vibes

I'm having some vibration issues with my Jeep. It's a 2000 cherokee with a 4.0l, 231 T case, Aw4 trans, 8.25 rear end. The vibes start around 65 and get worse on up. Its defiantly worse when I push on the gas peddle. I had the front driveshaft balanced, tires balanced twice. I'm doing the simple things to diagnose before I take to a shop. I've taken the front shaft out and that does not change anything. My question is if I take the rear shaft out and test drive in 4 wheel drive will the transfer case leak fluid out of the output shaft? This is the later design with the rubber boot over the output shaft.

not on a 2000. the tcase has an internal seal on the output shaft. pull the rear shaft and drive carefully. If you have never driven a 4x4 in front wheel drive its an interesting experience. It torque steers like crazy.

Try it without the rear shaft.
Do you have a lift kit? SYE?

No SYE and its all stock right now. Thank you to everyone that replied

your 2000 will have the external slip (wanna guess how I know). cut the band to remove the rubber boot, pull the rear shaft and test away without leaks. use a zap strap to retain the boot again if you don't wanna get the proper band, grease the shaft when you put it back on.

Are they vibes in the steering wheel or in the driveline? If you can feel it in the steering wheel I'd say it may be the start of death wobble which is usually bad ball joints. If in the driveline may be just a u-joint going bad. If so grab on to your driveshafts and see if you can twist them a lot with your hands. If there's a lot of play then you have a bad u-joint.

Take out the rear drive shaft and feel the joints first. They don't have to be sloppy to be bad. They could be dry and too tight.