bouncing up and down

[SGB]

Coulda used a thumbs-down icon too I guess. Up/Down. From about 45mph to about 55 mph the front end hops up and down. Bilsteins almost new. Kumhos are new and newly mounted and balanced (as is the alignment I guess I am about to UNDO). From outside watching, the wheels don't bounce, just the body, and from inside driving, the steering wheel does not transmit jiggles like the vibration is coming from the front at all. It was doing this before I got the tires to a lesser degree and I thought it was an out-of-round thing. Searching engine resaerch seems to indicate ball joints or ball-joint attachment point on the strut , but seems like that would make the steering wheel feel loose and I would feel more knockiong in the steering process. I've not replaced the ball joints or tie-rod ends ever. What do the voices of experience say?

[Tidybuoy]

The fact that the bouncing occurs between 45 & 55 mph sounds like a balancing problem. But, you say the tires are new and balanced. Maybe you should rotate the fronts to the rear and see if anything changes - if it does, then you've narrowed it to the wheels.

Ball joints can be checked visually and also you may want to jack up the car and try to wiggle the wheels - they should not move. Also do this to the rear wheels. The rears can be affected by the rubber bushings that get worn as well as rust under the battery which eventually spreads to the suspension.

If you've got original tie rods....they most likely need changing. I put the turbo tie rods on my car which basically stiffened the steering but really did nothing for the ride.

Lastly, check the torsion bars. Theres definately a left and right but I'm not sure what would happen if they were switched. The front torsion bar bushings also wear out but are fairly easy to replace.

Also, do you have Bilsteins on the front and rear or just the front?

Hope this helps..............Vern