[Statler]

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]

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]

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

[qa15ar]

i have this same problem, did you fix it?

[Statler]

I got the driver side repaired under warranty last July ('13) but the noise has come back again.

I had a look at the strut when I changed over to winters a few weeks back but there is nothing to see really. Not sure if I should spray a load of white grease up under the foam secondary damper or not - it's the bit the bellows for the damper rod attaches to.

I've a feeling it could be the strut..

[Jules59]

Originally Posted by Statler

I got the driver side repaired under warranty last July ('13) but the noise has come back again.

I had a look at the strut when I changed over to winters a few weeks back but there is nothing to see really. Not sure if I should spray a load of white grease up under the foam secondary damper or not - it's the bit the bellows for the damper rod attaches to.

I've a feeling it could be the strut..

I wouldnt cover the auxillary damper (aka bump stop) or damper rod with grease as grit will stick to it and cause it to wear more. It gets very mucky in those areas and difficult to clean.
My car makes the graunchy noise over speed bumps - im going to lube (very sparingly) the ARB bushes - easy job.

[Statler]

Let me know how you get on, I've no free time to try it this weekend.

[Icekube]

it will be one of the bushes on the front end, the bump stop doesn't do anything...