Dear AutoReportCard, can you help me with a problem?
My steering wheel shakes/vibrates when driving on the highway. It does not happen on a normal road under regular speed (<60 mph). The car is a Honda minivan, and the local garage has done a wheel balance check and even added new tires. I don’t think this is an alignment issue, and based on my previous experience I thought it might be due to a wheel imbalance. However, since that has been checked, perhaps it could be a suspension or under frame issue. What do you think?
A vibration like that, only at highway speed, if not a wheel balancing or tire problem, can be that the suspension bushings worn out. In some cases the bushing are separate pieces (BMW E46) and others they are integrated into the suspension, usually something like the “lower control arm” or something like that.
I also once discovered that a slightly loose bolt on the steering rack caused a similar type of high-speed vibration.
I guess it could also be that the shocks are completely dead (i.e. not damping) but then I would expect to see the tires “cupping” from bouncing all the time.
I hope that helps, ARC.