Front bump stops - BMW 3-Series (E90 E92) Forum

Statler · 07-31-2012, 07:40 AM

Just a quick query, some time back I had these replaced under warranty as the car was a little, for want of a better word, 'graunchy' over speed bumps.

In cars past it used to be the anti-roll bar bushings that did this and you lubed them up to fix. Bump stops were just inert lumps of rubber that sat on the top of the front suspension arm and connected with a pad on the chassis if the suspension compressed too much.

If I understand the BMW setup the front bump stop is part of the strut or something.

As mine have become 'graunchy' again, can anyone explain to me where they are, what they do and if they can be lubed to stop it?

(And, yes, I can turn the volume up on the radio to mask it

)

TIA
S

doughboy · 07-31-2012, 07:51 AM

Correct, a bump stop or 'additional damper' is just a rubber block on the damper shaft that softens the blow if the car bottoms out.

see: item 11 here http://www.realoem.com/bmw/showparts...16&hg=31&fg=10

Can't see how that makes any noise ever?

What's graunchy? Do you mean squeaky or a metallic noise?

I had my front ARB rubber mounts greased (with silicon grease) a while back as they squeaked a little, easy job, quiet as a mouse afterwards, and the freer movement of the ARB made the suspension more supple over small bumps.

Statler · 08-01-2012, 08:26 AM

Thanks for that.

You can hear it as the car drops down off the speed bump, not a squeak or metallic noise, if you say 'graunch' quietly that's exactly the sound. It's short and I generally don't hear it on normal driving.

I'll try the ARB bushings and see if that improves it.

Ta
S

07-31-2012, 07:40 AM	#1
Statler Major Pain in the Arse Drives: E92 320D M Sport Join Date: May 2010 Location: Northern Ireland Posts: 302 iTrader: (0)	Front bump stops Just a quick query, some time back I had these replaced under warranty as the car was a little, for want of a better word, 'graunchy' over speed bumps. In cars past it used to be the anti-roll bar bushings that did this and you lubed them up to fix. Bump stops were just inert lumps of rubber that sat on the top of the front suspension arm and connected with a pad on the chassis if the suspension compressed too much. If I understand the BMW setup the front bump stop is part of the strut or something. As mine have become 'graunchy' again, can anyone explain to me where they are, what they do and if they can be lubed to stop it? (And, yes, I can turn the volume up on the radio to mask it ) TIA S
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07-31-2012, 07:51 AM	#2
doughboy Major General Drives: E91 335i LCI Manual Join Date: Jan 2009 Location: UK Posts: 5,747 iTrader: (2) Garage List 2009 335i Tourer E91N [5.00]	Correct, a bump stop or 'additional damper' is just a rubber block on the damper shaft that softens the blow if the car bottoms out. see: item 11 here http://www.realoem.com/bmw/showparts...16&hg=31&fg=10 Can't see how that makes any noise ever? What's graunchy? Do you mean squeaky or a metallic noise? I had my front ARB rubber mounts greased (with silicon grease) a while back as they squeaked a little, easy job, quiet as a mouse afterwards, and the freer movement of the ARB made the suspension more supple over small bumps. __________________ JB4 15ohm - QUAIFE LSD - BIRDS B3 SUSPENSION - HARTGE ARBS - ETS FMIC - ER CHARGE PIPE - FORGE DVs- M3 FRONT ARMS & REAR SUBFRAME BUSHES - M3 STRUT BRACE - AR OCC - AFE DCI - BMWP SSK - RPI SCOOPS

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08-01-2012, 08:26 AM	#3
Statler Major Pain in the Arse Drives: E92 320D M Sport Join Date: May 2010 Location: Northern Ireland Posts: 302 iTrader: (0)	Thanks for that. You can hear it as the car drops down off the speed bump, not a squeak or metallic noise, if you say 'graunch' quietly that's exactly the sound. It's short and I generally don't hear it on normal driving. I'll try the ARB bushings and see if that improves it. Ta S