Suspension chatter after full refresh - Koni Special Active and H&R lowering springs

[youngsyr]

Can I ask why?

 

[gizlaroc]

When compared to the fiche below, my greatest concern is that it appears that a stop plate is between the bump stop and what I assume is the bottom of the bearing with housing, and I don't know if a further stop plate (the lower 6 in the fiche) is correctly between the bearing with housing (11 in the fiche). The other stop plate is below the top nut. I assume that the build up is wrong. Components could be missing (conical washer, 2 in the fiche which I supplied 4x) and / or in the wrong order.

Just slide the bump stop down and you will see if the washer is in there. That would make no difference anyway to be honest.


Regarding part 6, I can't see that would be missing.

 

[GBinSWE]

You're forgetting the diameter of the parts are different so some sit inside others. The part you've labelled 'bearing with housing bottom' is the middle of the top mount poking through the other parts, so the large washer (6) is in the right place. Also the no 2 washer won't be visible as it'll be inside the bump stop.

You are right - the large washer (6) was in the right place and the no 2 washer is not visible since it is in the bump stop.

By means of an update, I visited the Mechanic earlier. I took him for a short drive to demonstrate the chattering and then he put the car on a lift with the wheels suspended. We looked at the diagram of the build up and he explained that all parts were transferred over from the old bearing and that the bump stop is sitting correctly. The bump stops I supplied are not OEM but have been installed in the right way. It got interesting when he went around all four wheels and lifted them from underneath with his own strength. Three wheels offered resistance but the front left could be lifted up and down with significantly less effort. Conclusion is that damper fitted to the front left is defective - it is not damping correctly and hence the rattle especially audible to the driver (this being LHD).

Not what I (or maybe anyone else) expected in terms of a fault and also of the manufacturer's quality control... Importantly, trust in the Mechanic is restored who will fit the replacement as soon as I can get it to him .

I have started the process to get a replacement which will hopefully arrive quicker than the 10 days the original order took and update once it has been fitted.

Thanks all again!

 

[gizlaroc]

Can I ask why?

Because the garage put it in that way.

Then when I had the noise I took it all apart and while doing so realised these bump stops were too long for the new H&R springs.
So I cut an inch or so off them and then realised the garage had fitted them upside down. FFS!

To be fair, it won't make any difference, the stop is staying where it is meant to, the dust cover is still covering what it is meant to be covering, just a bit annoying and a niggle more than any thing.

I will put another one on at some point when I can be arsed.

 

[youngsyr]

Interesting. Sorry for all the questions, but I'm about to fit new bump stops onto B8s with H&R springs, so this is very relevant to me right now!

Are you saying that your bumps stops were too long for the lowered springs so needed cutting down, or that because of the incorrect installation they were too long?

Bottom line - do you know if my new bump stops will fit on my B8s with H&R springs?

 

[gizlaroc]

I had the standard bump stops, they also do them for the m030, which would be better with the shorter springs, the standard ones just looked too long, they took up half of the shaft nearly once under load.

Hence, when taking my stuff apart to put the hose and the support ring back in, I decided to cut the bottom of the bump stop off.

This photo shows the two bumps at the bottom (should be the top)...




However, when I went to do the other side I realised that the garage had put the offside one in, the one I had just shortened, upside down. Doh!

But I have driven it loads in anger and there is a dip near me that bottomed out my car on older OEM dampers that still doesn't hit the bump stops with it how it is.

This is the shorter one...


Part number 99634398009

 

[youngsyr]

Thanks - that confirmed my suspicion on seeing a different part number for the bump stops on the MO30 cars: they have shorter bump stops for their shorter dampers and springs.

I've ordered some to go with my B8s with H&R springs (which are shorter than the standard set up).

 

[gizlaroc]

I think the part is classed for the X74 option actually, which is 10mm or so lower than the M030.

But that is what I will put on mine when I can be arsed.

 

[GBinSWE]

To bring this to an overdue conclusion, my car went back to the workshop once 1x replacement front Koni strut and front top mount bearing parts had arrived for both sides. A different mechanic swapped out the defective Koni strut and replaced the bearings on both sides free of charge - somewhat generous since the issue was only with a defective strut being fitted to the one side and the build up of the bearings on both sides was fine and it was my choice to replace these) - and then another alignment check which I paid for. The result is no further chattering and despite the 30mm ride height drop, and now that it has settled in, a ride which is as comfortable as a standard set up. Roll is much reduced and I haven't found the tendency to understeer yet.

This allowed me to put some miles on over the summer so I could finish running in after the engine rebuild. After some initial tightness detected, it is now spinning nicely towards the redline from 6k rpm. So far, so good, all is stable, touch wood . It can soon be put away for the winter with no concerns.

 

[youngsyr]

To bring this to an overdue conclusion, my car went back to the workshop once 1x replacement front Koni strut and front top mount bearing parts had arrived for both sides. A different mechanic swapped out the defective Koni strut and replaced the bearings on both sides free of charge - somewhat generous since the issue was only with a defective strut being fitted to the one side and the build up of the bearings on both sides was fine and it was my choice to replace these) - and then another alignment check which I paid for. The result is no further chattering and despite the 30mm ride height drop, and now that it has settled in, a ride which is as comfortable as a standard set up. Roll is much reduced and I haven't found the tendency to understeer yet.

This allowed me to put some miles on over the summer so I could finish running in after the engine rebuild. After some initial tightness detected, it is now spinning nicely towards the redline from 6k rpm. So far, so good, all is stable, touch wood . It can soon be put away for the winter with no concerns.

Sounds like you've found the ideal solution for people wanting the standard ride comfort at a lowered height.

 

[GBinSWE]

The H&R springs on paper give a 30mm drop but I suspect may be closer to 20mm in reality. My old standard springs may have been sagging before but the drop with the H&Rs fitted is not so extreme that I fear speed bumps and have not yet bottomed out even with the deeper sump fitted. My only concern is longevity of the dampers, since one was defective out of the box and I have heard that in some other applications (Skoda) that after 2 years or so they are toast. We'll see, it is not a daily driver, so they may be fine.