arthritis?

[Leah Mueller <muellerl@cadvision.com>]

After we got some new snows mounted today (Pacemark High Traction GTR
195-65R15 - budget couldn't handle the big names - but these tires look
real mean anyways) I am now hearing a groan from the rear passenger side
when going over a bump such as turning onto a street out of a parking lot.
When I bounce the car up and down at the left rear wheel, I get a quieter
version of the same groaning.  The car is a 86CDtq.  Is this strut,
springs, bushings, or parking brake caliper that is essentially useless?  

Thanks for your continued help of a green horn.  I searched the arhives in
various ways but could not find a suitable post

David