elvis1962

Vibrations can have a lot of sources, as you know and this may not be yours. My 1991 lexus LS-400 is now perfectly smooth but it took some work. I had a vibration at about 60 on up. It felt exactly like two or more out of balance tires. It wasn't severe but enough to aggravate me every time I drove the car. I changed tires and balanced for a year. There was some improvement but I kept getting the impression that even with a "perfect balance" I would still have some noticeable shake. This proved to be correct as I found out when I finally did fix this problem. The solution was new lower ball joints. My 91 LS-400 had a design problem. The lower ball joints have an internal, nylon-type device made to keep grease in the right place to prolong ball-joint life. It was designed incorrectly and actually kept grease away from critical wearing surfaces. Newer ball joints have been improved to eliminate this flaw. Once replaced, the car runs perfectly smooth. There was enough play in the old ball joints to allow the front wheels to move slightly under the dynamic load of 60 mph and up. The end result was a vibration that felt the same as an out-of-balance tire. Just about any front-end component with excessive play can do this, but checking the ball joints is a good place to start. I don't believe the car is overly sensitive to tire balance now. I also changed the upper ball joints and lower control-arm bushings. These were changed later to tighten up the steering but the vibration was gone from the earlier fix. What an inprovement. The car rides and handles like new. It has 135,000 miles at this time.

Craig, Vibrations can have a lot of sources, as you know. I had a vibration at about 60 on up. It felt exactly like two or more out of balance tires. It wasn't severe but enough to aggravate me every time I drove the car. I changed tires and balanced for a year. There was some improvement but I kept getting the impression that even with a "perfect balance" I would still have some noticeable shake. This proved to be correct as I found out when I finally did fix this problem. The solution was new lower ball joints. My 91 LS-400 had a design problem. The lower ball joints have an internal, nylon-type device made to keep grease in the right place to prolong ball-joint life. It was designed incorrectly and actually kept grease away from critical wearing surfaces. Newer ball joints have been improved to eliminate this flaw. Once replaced, the car now runs perfectly smooth. There was enough play in the old ball joints to allow the front wheels to not control the tire. The end-result was a vibration that felt the same as an out-of-balance tire. Just about any front-end component with excessive play can do this, but checking the ball joints is a good place to start. I don't believe the car is overly sensitive to tire balance now.