S6 Suspension overhaul.

[Vorsprung durch Technik]

I'm about to change the front shocks with Bilstein B6 inserts in a few days time,but seam to remember it's not so straight forward a job as it might seam. There was something about drilling the bortom of the strut to prevent future problems with the B6 insert. Can any of you shed some light on this and or the latest wisdom for a fit and forget and long life of the B6 insert?

Cheers guys.

[UrS4boy]

I'm about to change the front shocks with Bilstein B6 inserts in a few days time,but seam to remember it's not so straight forward a job as it might seam. There was something about drilling the bortom of the strut to prevent future problems with the B6 insert. Can any of you shed some light on this and or the latest wisdom for a fit and forget and long life of the B6 insert? Cheers guys.

The drilling was to let accumulated water out so it wouldn't freeze in the strut housing and cause problems.

[Vorsprung durch Technik]

EE intensiva P

The drill was to let accumulated water out so it wouldn't freeze in the strut housing and cause problems.

That's it,but what was the reason for this? It wasn't necersary for the standard set up and due to the much larger piston the original Bump stops don't fit either? Is there a solution to this problem? I'm assuming theres no problem fitting the shock absorber protective sleave pnumber 431412175D. Dave,the intension of this thread is to obviously help me but also to put all the usefull tips / nuggets of written info buried in other threads to make this one a one stop shop with all the usefull/important relevant bits of info here for others.

[hunker7]

EE intensiva P

That's it,but what was the reason for this? It wasn't necersary for the standard set up and due to the much larger piston the original Bump stops don't fit. I'm assuming theres no problem fitting the shock absorber protective sleave pnumber 431412175D. Dave,the intension of this thread is to obviously help me but also to put all the usefull tips / nuggets of written info buried in other threads to make this one a one stop shop with all the usefull/important relevant bits of info here for others.

You could try and increase the size of the piston hole in the bumpstops?

[UrS4boy]

That's it,but what was the reason for this? It wasn't necessary for the standard set up and due to the much larger piston the original Bump stops don't fit either?

Different design, as pointed out previously by Thuppu. Also Bilstein EDIT: Front Strut inserts have built in bump stops so you do not need the external OE bump stop.

Hmm, have you used Bilstein B8's upside down monotubes with the open bottom structure? I would belive a full filled strut would destroy it if there is no room for expansion, it would be like a solid pipe instead of a shock when the lower chamber is full of liquid. Also when I now finally found a cross-section pic of the structure I can't tell there would be any benefit using any antifreeze in the strut at all.



If using these Bilsteins I would still recommend drilling the drain holes in the bottom of the strut.

[maiks]

Rear ones don't have build in bump stops.

[UrS4boy]

Rear ones don't have build in bump stops.

Different design, as pointed out previously by Thuppu. Also Bilstein EDIT: Front Strut inserts have built in bump stops so you do not need the external OE bump stop.

[Vorsprung durch Technik]

Thanks Maiks.


Thanks Dave,great to learn Front B6 inserts have internal bump stops. As far as the water ingress problem,surely it would be better to modify pt number 431412047B and 431412389B (cap for protective rubber sleeve) so the protective oem rubber sleeve can be used. Has any one been able to do this?

[maiks]

Just mentioning

[UrS4boy]

Thanks Dave,great to learn Front B6 inserts have internal bump stops. As far as the water ingress problem,surely it would be better to modify pt number 431412047B and 431412389B (cap for protective rubber sleeve) so the protective oem rubber sleeve can be used. Has any one been able to do this?

Mark: I really thinking that *you* are overthinking this. A lot.

I have been running B8 Sport inserts with Eibach springs since 1999 on my UrS4. I never drilled the strut housing and I only run the big rubber bellows, nothing more, as shown below. (A photo taken in 2011 when I changed the white plastic ball bearing (both sides) when I redid the front suspension (same springs and same 1999 strut inserts)):

[Vorsprung durch Technik]

I'm not overthinking anything! What's the need to drill a hole in the bottom of the strut as some recommend yet you have never done this. Is it possible to be able to fit the rubber protection sleeve using B6 shocks? I would think if you can why drill?

[UrS4boy]

I'm not overthinking anything! What's the need to drill a hole in the bottom of the strut as some recommend yet you have never done this. Is it possible to be able to fit the rubber protection sleeve using B6 shocks? I would think if you can why drill?

You *ARE* overthinking it.

I didn't need to drill anything because I live in Vancouver BC. It doesn't get cold enough to worry about a little moisture in the strut housing causing problems.

Modify the protection sleeves if it makes you feel better. Nobody else that I know of on other UrS forums has done that when switching to Bilstein B6 HD or B8 Sport strut inserts on their C4 UrS4/6s.

Good luck.

[Vorsprung durch Technik]

Ok proffesor. A simple question for you.how does water/moisture get in the strut when it's torqued down and it has the protective sleeve fitted keeping moisture out?

[UrS4boy]

Ok proffesor. A simple question for you.how does water/moisture get in the strut when it's torqued down and it has the protective sleeve fitted keeping moisture out?

Because no matter what you do, the seal and/or sleeve are not 100% effective in keeping water totally out. Generally this would not be an issue but perhaps in a very wet climate with subsequent freezing temps, it could be. Hence *SOME* (not all) people have drilled a hole in their strut housings to prevent the build up of moisture.

I really think that you are worried about nothing in your climate. If you think otherwise, take the precautions that will make you feel less worried.

Again, good luck. I can't help you any more on this topic.

[Vorsprung durch Technik]

Ha, you just did help.Make sure the top and bottom of the sleeve is sealed properly with a little help.