Steering wheel shuddering problem at highway speeds

I've got a bit of a problem with my Volvo. 1988, 240 GL. The
steering wheel shudders at high speeds. It's fine until I hit 55 MPH
or so, then it makes a clacking noise while shuddering. The steering
is not affected.

I recall having this problem six months or so ago. Went away when I
got new tires - or at least that's what I recall, memory could be
incorrect. After getting the new tires I noticed that the steering
seemed loose at high speeds. I took the car in for servicing recently
and they fixed the brakes and rotated the tires. They said the
steering column looked fine.

Any idea what this is? It's more of an annoyance than a real
problem. I live in Orange County, near Los Angeles, and it's not
common for freeway speeds to get over 50 MPH. I could just live with
it until I junk the car, which could be just a few months. But if I'm
courting disaster, I'd like to take care of it.

Any help or opinions is appreciated.

 

That happened to my 1986 240 DL, if I remember correctly it was front
wheel bearings and/or steering rack. Carter

 

Nowhere in your message is there an indication that someone balanced
the wheels - if that hasn't been done, then have that service
performed. If that isn't the problem it is all but impossible to
correctly diagnose the precise cause of a vibration via the internet.
You will likely end up with a long list of possible causes that won't
be particularly useful unless you have the skills to undertake
analysis and repair at home. I would take the car to a Volvo
dealership or a local mechanic that specializes in Volvos for an
evaluation.

A vibration like that could be caused by serious condition like a
bubble in the tire sidewall, so do get it checked out.