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mystic_525_tds
06-21-2008, 05:21 AM
i have been having trouble with a bump/knocking noise from the front suspension, i took off the passenger side strut as i suspoected the top mount, so i replaced the top mount and found the drop link from the anti roll bar (sway bar to usa guys) was worn so i replaced this, i also found the shock absorber has a little vertical play in the strut so i fixed that.

i still have a light bump noise from that side, its a lot quieter than before but it does not happen when going over bumps, it happens when driving along and the car is going over unreven surfaces on the road, i can cause it to happen by pressing on and off the gas in 3rd gear, as the lifting and dropping motion on the front creates a slight bump noise.

i could not find anything else with play on the front passenger suspension so i am at a loss, i noticed the rubber boot on the lower arm balljoint was shot even though it was replaced 2 years ago by previous owner, but i dont feel any pal on the balljoint so any suggestions how to check this balljoint properly or how to find where the bump is coming from ?

cheers guys

ThoreauHD
06-21-2008, 12:42 PM
I have the same problem. Half of it for me was the control arms, and the other half were the sway bar links. 10 dollar part. It sounded like holy hell driving over a bump. I thought my front end was going to fall off and I'd have to beat my mechanic to death after I got outta the hospital. But for you, I don't even have to play sigmund freud.

"i noticed the rubber boot on the lower arm balljoint was shot" Well, I'd be looking hard at the control arms and bushings. They may not have play when you're wiggling it, but when 1000lbs wiggles it, it may not be so happy. If one piece of rubber is rotting out, odds are good that the rest are **** too.

e34.535i.sport
06-21-2008, 03:28 PM
To check the control arm ball joint jack it up with the wheel on... Get underneath and look at the balljoint as someone tries to turn the wheel by grabbing it at 3 o'clock and 9o'clock by wiggling it- I could see the balljoint moving around and the wheel had a lot of play.

Also check the anti-roll bar mount bushes...