With an unlimited with adjustable CAs and jereel shafts, do you expect drive line vibration to increase as lift increases? Or, to be precise would you expect a 4.5" lift to vibrate more than a 3" lift?

If so, (same setup) is there a lift height that has no perceptible vibration?

 

Where you'll feel the vibrations is on the front drive shaft and those can be gotten rid of by reducing your caster. This is somewhat of a pain because at 4.5" of lift, more caster will help keep your Jeep driving straight but vibes aren't a good thing and it's better to get rid of them or at least, as much as possible.

 

but is a little vibration going to hurt anything or just be annoying?

 

Forgive me if this is obvious. So, it is easier to avoid vibes with less lift? Meaning it is easier to find a compromise in caster angle to eliminate drive line vibes and maintain handling?

 

As with any type of machinery, vibrations and noises or excessive temperatures need to be eliminated to prevent premature mechanical failures.

 

Nothing to forgive as your question is a good one. And, to answer it, yes, less lift will cause less of an angle on your drive shaft and this will reduce your chances of getting vibes even if you have more caster.

Exactly - mainly you will see failures in things like seals causing leaks and eventually your u-joints.