Excellent suggestion to weigh the whole rig, one axle at a time. Will do it. We do have a weight distribution hitch (similar to the picture you sent) but with a separate bar on the outside that can be cinched to act as a break against sway. Bear in mind we towed the same camper with a 1999 RX 300, having the same towing rating, without any of the tire issues we now experience. Significant?
Cupping is usually associated with bad shocks/struts, but it is not always caused by this. I had this very problem with a brand new Honda Civic in 1993, only more severe, the tires were badly cupped and worn out every 5000 miles. The dealer would realign it (it was always out of alignment when they checked) and put on new tires. It stopped when I had the alignment done by an independent shop with a good reputation.
Give the dealer another chance. They may need to have their alignment rack calibrated.
Thanks for the tip. Lexus just tested the alignment and passed the car with flying colors. But my private mechanic – the one who bets on bad struts – also found the alignment okay.
Any chance you were provided the alignement specs and could post them here? Many late model alignment racks provide a computer printout and you should have been given this.
An additional question would be did the Lexus dealer charge you for this alignment or was this considered to be a “warranty deal”? Most private mechanics do not do alignments so does your mechanic do them or farm them out? How much did he charge you for rechecking this?