Well, you did give him the answer he wanted, Rod, but what's the method to do that with any accuracy?
Do you know Rod?
I'm really surprised the spec is really that large of an allowance. I'd bet the state inspectors here in Va and a front end tech would reject it at that amount. The inspector pretty much doesn't want to feel any movement in the suspension and bearings by shaking and yanking on the tires while elevated. Likewise, when you have the front end aligned, any movement is not allowed to perform such. This problem is both detectable by the computerized system and manually as per above. So, for me, I do the manual "shakedown" both as a preventative measure and to diagnose an existing problem typically indicated by rattling, creaking and other noises. If you are suspicious of something, just replace it. You'll probably need to anyway since you will want to perform an alignment after replacing even just the one. The expense of the alignment alone might be enough motivation alone to replace both so as to not to redo the alignment after replacing it at another time.