About 2 years ago I emailed PW tech and they responded quite quickly with the specs for my year PW. So here's a question for you: If I'm not having any tracking issues (if I let go of the steering wheel it stays going straight ahead and doesn't pull one direction or the other) does one risk having an alignment? It seems like you'd do that to correct problems and not as a matter of routine, correct?
(And BTW: Thanks for all of your posts. A great source of info.)
I would add one more requirement to your test and that would be how easy it is to correct when hit by a big wind gust from various directions. And of course a look for uneven tire wear.
In the past, for rear wheel drive vehicles, I would have said it is good to have it checked every couple of years, and if it is going straight and not showing abnormal wear leave the caster the same, maybe get the camber even and slightly positive if it is not that way, and adjust the toe to make sure it is in the proper amount.
With all the issues that we, and others, have been seeing with the current accuracy of wheel alignments, I really don't know what to say. My instinct would have been if it is going straight just get the toe right, but we just had an example where the freshly set toe was horrible, so even that gives pause.
The safe thing would be if you can find a truck place that still uses the manual gauges and then just have them check caster and camber and show you what they are. If they look OK and it goes straight just have them set the tow with the old style pointer gauge.
Hopefully, things will get worked out with the new machines and incompetent techs so we can get good alignments with the machines, but we are 5 for 5 being poor to horrible on the last 5 alignments. It is to the point I am trying to get setup to do them at home, and will be getting a first shot at it when the snow is gone. I have the gauge and turntables and am in the process of making a decent toe gauge, so we will see.
I wish I had a better answer for you, but I don't think there is one unless you can find a very good shop that does a good job. The rest of us have not found that to this point.