My 99 Deville with 118,000 has a wheel problem. When I go into a right curve on the highway the right rear wheel seems to be bouncing at a rapid pace. It sounds like someone is using a air hammer in the trunk. If I turn the wheel just a little bit to the left and slightly straighten it out the thumping stops. As soon as I get back to making the curve it starts right up again. It is also vibrating and making the noise at the same time. What do you think it is?
Thanks in advance,
Bill.

id jack that corner of the car up and remove the tire , and look it over for a "bubble"on the side of the tire that faces the inside of the car..even beatter throw the spare on and see if that cures it ...if that dont fix it there may be something screwy with the shock on that corner ..but i really think its int he tire , its either seperateing or some other problem , have this taken care of ASAP

I removed the wheel and no bubble on the tire but the bushings in the knuckle are shot. So far the best price I could find for the knuckle is $254.67 + $50.93 shipping for a total of $305.60 from gmpartsdirect.com. Anybody know where they are any cheaper?