Those with lowering springs...fain't knocking going over light bumps steering turned?

Alan l. · 07-21-2018, 10:06 PM

So my F80 has 400 miles on the odometer. Macht Schnell springs installed literally day one and now that i've had some seat time with the car I noticed that when going over very light bumps especially with the steering wheel turned there is a knocking sound coming from the front of the car. I don't think its installer error because my mechanic has been doing my bmw suspension install for years and he knows what he's doing. Again my car is brand new ZCP M3 so its not worn parts either.

Is this noise simply from having not enough preload on the spring since they are shorter?

I also thought I read in another post that it had something to do with the need to adjust the steering system angle due to the lower ride height...

On dips or regular bumps you don't notice the noise but when its really light bumps you notice it especially if you are turning at the same time.... Any ideas?

Alan

nathanielredmon · 05-16-2022, 08:55 PM

I have the same problem

FrozenGT · 05-17-2022, 07:50 PM

From my understanding it comes when you lower the car too much in the front without camber kit.

My recommendation would be to get the e MPERFORMANCE HAS Kit. Yes it's expensive but you can control the ride height. I have it on my 2020 M4 competition and I don't have any issues with knocking. I have a one and a half finger gap BMW recommended ride high all way around.

Alan l. · 05-23-2022, 09:00 AM

There was a separate (long) thread that resolved this. Turns out it was the steering rack bolt that needed another 1/4 turn that eliminated this completely.

Alan

Nyc911 · 05-24-2022, 02:46 PM

I had a similar problem, mine sounded like someone hitting a hollow metal pipe or drum from the right really pronounced on the left side. I thought something was not torqued correctly, but it turned out that the preload needed adjusting ones it was properly set the noise went away. I have KW DDC coilovers

Not sure if you have the same problem but worth having the installer make sure the pre-load on the front suspension is correct

hC1001 · 06-01-2022, 08:13 AM

Try retightening the sway bar endlinks. They can also make thudding noises when not tightened enough.

07-21-2018, 10:06 PM	#1
Alan l. Major General 5437 Rep 8,808 Posts Drives: 2020 F95 X5M Competition Join Date: Jun 2009 Location: United States iTrader: (9)	Those with lowering springs...fain't knocking going over light bumps steering turned? So my F80 has 400 miles on the odometer. Macht Schnell springs installed literally day one and now that i've had some seat time with the car I noticed that when going over very light bumps especially with the steering wheel turned there is a knocking sound coming from the front of the car. I don't think its installer error because my mechanic has been doing my bmw suspension install for years and he knows what he's doing. Again my car is brand new ZCP M3 so its not worn parts either. Is this noise simply from having not enough preload on the spring since they are shorter? I also thought I read in another post that it had something to do with the need to adjust the steering system angle due to the lower ride height... On dips or regular bumps you don't notice the noise but when its really light bumps you notice it especially if you are turning at the same time.... Any ideas? Alan __________________
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05-16-2022, 08:55 PM	#2
nathanielredmon Enlisted Member 9 Rep 38 Posts Drives: 2015 BMW M4 YMB, 2014 Audi Q7 Join Date: Sep 2021 Location: Boulder, Colorado iTrader: (0)	I have the same problem
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05-17-2022, 07:50 PM	#3
FrozenGT Captain 1117 Rep 839 Posts Drives: 2021 Z4 M40i - Lexus NX300 F Join Date: Oct 2019 Location: Ashburn VA iTrader: (1)	From my understanding it comes when you lower the car too much in the front without camber kit. My recommendation would be to get the e MPERFORMANCE HAS Kit. Yes it's expensive but you can control the ride height. I have it on my 2020 M4 competition and I don't have any issues with knocking. I have a one and a half finger gap BMW recommended ride high all way around. Attached Images
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05-23-2022, 09:00 AM	#4
Alan l. Major General 5437 Rep 8,808 Posts Drives: 2020 F95 X5M Competition Join Date: Jun 2009 Location: United States iTrader: (9)	There was a separate (long) thread that resolved this. Turns out it was the steering rack bolt that needed another 1/4 turn that eliminated this completely. Alan __________________
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05-24-2022, 02:46 PM	#5
Nyc911 First Lieutenant 187 Rep 312 Posts Drives: Porsche 997.1 Join Date: Sep 2021 Location: NYC iTrader: (4)	I had a similar problem, mine sounded like someone hitting a hollow metal pipe or drum from the right really pronounced on the left side. I thought something was not torqued correctly, but it turned out that the preload needed adjusting ones it was properly set the noise went away. I have KW DDC coilovers Not sure if you have the same problem but worth having the installer make sure the pre-load on the front suspension is correct
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06-01-2022, 08:13 AM	#6
hC1001 Captain 591 Rep 987 Posts Drives: E36 M3, F80 M3 Join Date: Nov 2019 Location: Brooklyn, NY iTrader: (4)	Try retightening the sway bar endlinks. They can also make thudding noises when not tightened enough.
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