You post is interesting...
Maybe I should start with the recommendation of Rough Country: 4.6 deg.

 

My Currie installation PDF says that "the frontend must have 2-3 degrees of caster". What gives?

 

as a bare minimum, i could see that. or, to insure that you won't have vibes, i could see that too. but, for handling purposes, 2°~3° really isn't gonna do the trick.

 

I didnt read through all the replies, but in short. When it comes to caster settings... They higher you can get it the better. There is a point where drive line angles come into play so there is some give and take. anything over 5 will help avoid DW. If you can get it to a 6 without killing the driveline angles you will be golden. Ive learned this over the years with many a lifted TJ and my JK is no different.

 

of course, if you were to install a set of solid spyntec manual hubs, you wouldn't even really need to worry about driveline angles.

 

exactly. but who wants to get out and lock the hubs in all the time.

 

You'll have 10 different answers because you'll have ten Jeeps using ten different setups. I don't believe that caster and death wobble are related in the least. The only negative effect of too much caster will be an unstable feeling when cornering. Almost as if the Jeep wants to "tip over". The reason for this is because, as the steering axis is tilted further and further back at the upper ball joint, you are actually picking the Jeep up to make a turn. That effect already exists because caster is set at a positive angle at the factory, but increasing caster has an exponential effect on that sensation. I think most are happy in the 5-6 degree range. Any more than that, and I think you run the risk of the above mention condition. Any less and it might not have the highway manners you're looking for. Lastly, I see some people trying to make a connection between caster and vibration. There is not an alignment angle that causes vibration. Vibration is caused by something loose, out of balance or out of round tires or bent or out of round wheels. That's about it. Alignment angles can contribute to some bump steer, but I don't think that's what we're talking about here.

 

We actually believe the vibes are coming from the rear shaft at this point. I'm having the rear DS rebalanced next to see if its the cause of the vibe. If rebalancing doesn't do it then I'll reset the caster to 4.5 to see if that helps the front.

 

That's disinformation because its just not right. Flexing the CV too far outside of its tolerance will cause vibration. Trust me, I've tried a lot of angles on my front caster and you feel the difference. Granted, you're right that its about 99% what you said, but caster can contribute.

I think if you're too off camber that would contribute as well too, don't you think?

 

I mentioned this in a different thread, but it wasn't answered as thoroughly as I would like. So here goes again.
When I put my angle finder on the ground, it says 0, so the ground is level. When I put it on the hub, it says 7. However, when the Jeep was aligned, they said the caster was 4.4 and 4.6. So is the measurement we are taking at the bottom not the true measurement?