first, i guess you have a e34.
new thrust arms helped me solve a similar problem. you can buy them at www.racingking.net
... (i recommend racingking...bought plenty of stuff from them and they seem great).
RacingKing: just go to the apropriate car section on the left. then you will see it listed as Lemfoder Thrust Arm w/ Bushing, without Bushing or just the bushing.
BMA: Select year and model and go suspension
BavAuto: Select year and model and hit suspension.