DamianC

1999 Lexus RX300 with 300,000 miles has uneven tire wear on front tires, with the outside wearing badly. A friendly mechanic said it needed control arms, and just aligning wheels would not fix this.

05RX330AWD

I actually went through something similar although only for one tire in the rear of the RX. I suspected a weak rear shock. My mechanic is honest & reliable looked at the wear & the shock although felt the shock was fine as were all other parts but I should check with someone that specializes in alignments.The reply there everything looks fine including the alignment. When I went to put summer tires on, it was then the shock showed leakage, that was the issue all along. Although this was in my case.
You will find a photo of the tire & wear in this link:
https://www.clublexus.com/forums/rx-...-struts-2.html

thomas1

Could be bad ball joints.