Originally Posted by Overlander
So what's the verdict? any arguments for or against them? I have a set sitting on my shelf, and wondering if I should install them on my 110. just got my rig, and not clear on whether my lift is stock or not, but seems visually to be riding high. I'm happy enough with the suspension and steering right now, but would be interested in mitigating any driveline stress.
Incorrect castor won't really cause any additional stress on the driveline. If you do not feel vibrations (from driveshaft angles) and the steering feel is good, you are likely not lifted, or only mildly lifted (or the castor has already been corrected one of a number of ways). If the castor was out significantly, you would know it by the hard pull when you step on the brakes hard, the lack of self centering in the steering, etc.
As for the Castor correcting bushings, the only downside I am aware of is that they limit front axles articulation (not a strong point to begin with) because they reduce the amount of area for flex to take place where the radius arms bolt to the axle housing, because they reduce the amount of bushing material.