I have a 2000 gs300 I have replaced the LBJ, TIE RODS, control arm bushing, and then an alignment it drives good until I go over a dip in the road and it starts to shake on the front driver side wheel, what could it be, this only happens on the freeway above 50mph?

 

Have you checked your shock condition? I had the same type of problem and it was caused by a dead shock..

 

Yeah something wrong with the shocks if all else were replaced go KYB