Re: Strange Suspension problems

["Rob Reesor" <reesor@tss.com>]

On Oct 31,  1:23pm, HUDSON, HEIDI wrote:
> Subject: Strange Suspension problems
>      Anyone who could help figure this out???
>
>      I bought a set of new tires a week ago.  In process of attempting to
>      align the car, it was determined that the left front side could not be
>      aligned and required a trip to the frame shop.  (Although I bought the
>      car used, I've supposedly had it aligned twice with no problems.  The
>      ride was "rougher" than I was accustomed to, but I attributed it to
>      the quattro suspension).
>
>      I had the tires mounted and balanced and made an appointment for the
>      next day at the frame shop.  I drove the car home - approx. 15 miles.
>      On the ride home, the car began to vibrate badly at 60 mph on the
>      expressway.  I got off the next exit to check the tires, and it went
>      away as I slowed on the ramp.
>
>      The next day frame shop adjusted the front end and I then had a 4
>      wheel alignment done.  The first day out of the shop it seemed great -
>      a much smoother ride.  Yesterday at 40 mph the car began to vibrate
>      again.   It continued for 1/8 mile until I stopped for a light.  As I
>      slowed down, the vibration sounded like a rhythmic thump related to
>      the turning of the tire.  It seemed to be coming from the left front.
>      When I started up again from the light, it was gone.
>
>      Doesn't seem to happen at a particular speed and it goes away for no
>      apparent reason.  It's also very brief in duration.  It happened
>      before the frame shop touched the car, so I don't think it was
>      something they did.  The tires were the only change - could it be the
>      tires?  It never happened before these tires were installed.  What
>      could cause this that would spontaneously go away?
>
>      I'm stumped - any suggestions?  Any help would be appreciated.  By the
>      way, its a 1988 90Q.
>
>      TIA
>      Heidi
>      hhudson@rimail.interlan.com
>-- End of excerpt from HUDSON, HEIDI

A bad tire could do this, but I think it would be constant or at least constant
at some speed. A splice separation or a bubble could cause a thumping vibration
at particular speeds or on corners.

-- Rob



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