1984 Jeep CJ7 Vibrating when in gear

Ok sounds like a clutch or a throw out bearing retainer problem. If I am understanding right when the clutch is engaged you have a vibration and when you step on the clutch pedal and disengage the clutch the vibration goes away. Is that correct?

Ok then it could any one of these problems clutch pilot bearing throwout bearing retainer on the end of transmission or the front bearing. Unfortunatly you won't know which it is until you take it apart and check it all out. Don't forget to turn the flywheel if you need to replace the clutch, make sure they have a turntable type and cut it with a stone not a brake lathe.