knocking rear noise

[epp]

can anyone pls tell me what this knocking noise might be..it only happens at a speed of 15-20km then it disappears as i go into speed. i have changed the entire rear suspension including the springs, sway bar links, rotors among others. the brake pads are still alright. you wont hear the knocking if the radio is on - even on low volume..but it doesn seem to want to go away..

very grateful on any guesses..

rgds,
ed
90 535ia

[Robin-535im]

can anyone pls tell me what this knocking noise might be..it only happens at a speed of 15-20km then it disappears as i go into speed. i have changed the entire rear suspension including the springs, sway bar links, rotors among others. the brake pads are still alright. you wont hear the knocking if the radio is on - even on low volume..but it doesn seem to want to go away..

very grateful on any guesses..

rgds,
ed
90 535ia

but only if it increases with road speed. Is a result of going over a bump, or just a function of driving straight and level?

Biggest clue would be if it gets faster as you go faster - in that case it's something in the driveline or something connected directly to the driveline, like drive shaft, rear end, CV joints, guibo, etc.

[epp]

Thanks very much for the info..that narrows the guessing i need to do..it disappears as i pick up speed..next thing is to jack the car up and have
a listen..could probably be the breaks, or the hand break..

rgds,
ed.

but only if it increases with road speed. Is a result of going over a bump, or just a function of driving straight and level?

Biggest clue would be if it gets faster as you go faster - in that case it's something in the driveline or something connected directly to the driveline, like drive shaft, rear end, CV joints, guibo, etc.