[masraum]

Originally Posted by gchappel

Makes sense- kind of.
Again I thought it was based on chassis and wheel- did not realize tires would make a difference.
I will give them the benefit of the doubt- although our local jeep dealer has the worst service department I have ever used.
thanks for helping me understand
gary

Yes, chassis and wheel, but, imagine if you will, that you had 3 tires sitting on flat level ground, but the fourth tire was sitting in a 2" deep depression (or 2" tall platform, for the purposes of exaggerated illustration of 1 wonky tire). That corner of the vehicle's suspension would be compressed or in droop (and to a lesser extent, at least one of the other corners would be a little off). You couldn't reliably align the vehicle like that. It would be like aligning a vehicle with 3 good tires and a compact spare. You need all 4 tires to be in similar shape and with similar air pressures so that they load the suspension evenly. It would also be like getting an alignment with a car with a horribly wonky corner balance.