Bilstein B6 Inserts for urS6 HP2 Struts

[waveydavey]

I've taken delivery today of a pair of Bilstein B6 Sport inserts for my HP2 struts that I'm getting ready to fit to my C4 A6 TDI. On checking them though I find the inserts are 46mm diameter whereas the struts are 49mm internal diameter. Strikes me something isn't quite right as I've always thought inserts should be a tightish sliding fit into the strut and not a loose fit. Part number is 34-003701 which as far as I can see is correct. I know there is a difference in diameter between normal B4 and S2 inserts so I'm wondering if I've fallen foul of a similar issue with the C4 chassis.

Anybody have any previous experience of fitting these inserts that can shed a bit of light on my 'problem'

Thanks in advance

David

[macspring]

David,

Any update on what happened ?

Thanks.

[UrS4boy]

David, Any update on what happened ? Thanks.

Not the David you refer to but seeing that I have HP2 struts on my 94 S4 V8 avant with the 1BE sport suspension (originally), I suspect the correct strut inserts should have been the B8 sport versions, not the B6.

[Thuppu]

The Bilstein inserts are smaller in diameter than the strut tube ID, B8's are just the same. They are ment to be torqued down with the top nut, no problem with that.

[macspring]

Thanks guys.

[UrS4boy]

The Bilstein inserts are smaller in diameter than the strut tube ID, B8's are just the same. They are ment to be torqued down with the top nut, no problem with that.

And by top nut, you mean the Bilstein one that is supplied with the strut insert, I presume.

I have heard of people who were concerned about the insert rattling around in the strut tube wrapping the last 19mm or so of the insert with multiple passes of electricians tape until the OD of the insert is closer to the ID of the strut tube.

[quattrostyle]

The Bilstein inserts are smaller in diameter than the strut tube ID, B8's are just the same. They are ment to be torqued down with the top nut, no problem with that.

And before fittng the dampers filling the strut with oil or coolant I presume?

[diesel des]

With bilstein isn't there a requirement not to fill the housing with fluid and instead drilling a hole at the bottom of the housing to let fluid out?

[quattrostyle]

I don't know. I use fluid in the struts everytime I change dampers on my cars. When the fluid is level with the top of the strut once the damper is installed no more fluid can get in so there is no need to let fluid out by a hole in the bottom of the strut
Oil or coolant in the strut around the damper should have a cooling function for the damper AFAIK?

[Thuppu]

This has been discussed before on the forum. Never ever fill the strut with oil if you use Bilstein upside down shocks! They have air vents in the bottom, and the shock itself will be filled up, that will cause a failure when the shock can't compress anymore.



It's also well known that water can go inside the strut and will do the same thing, destroy the shock. So it's good to drill small water drain holes in the bottom of the strut.

[Thuppu]

And by top nut, you mean the Bilstein one that is supplied with the strut insert, I presume.

I have heard of people who were concerned about the insert rattling around in the strut tube wrapping the last 19mm or so of the insert with multiple passes of electricians tape until the OD of the insert is closer to the ID of the strut tube.

Yes. The cartridge isn't moving anywhere if torqued down properly. The strut bottom is like a cup and the bottom of the shock will have the same form. Klick!

[Cordoba16vt]

So do we use B6 or B8 shocks with the 1BE suspension ?

Or we go straight to lowered springs and B8 shocks

What do you suggest?

[Yaz]

B8's are shorter versions of B6's, if you are using lowering springs more than about 40mm then you should use B8 dampers.

So do we use B6 or B8 shocks with the 1BE suspension ?

Or we go straight to lowered springs and B8 shocks

What do you suggest?

[quattrostyle]

This has been discussed before on the forum. Never ever fill the strut with oil if you use Bilstein upside down shocks! They have air vents in the bottom, and the shock itself will be filled up, that will cause a failure when the shock can't compress anymore.

Well that's very good to know, I take it that is explained in the manual that comes with upside down shocks?

[diesel des]

What happens if you use b8 on a car lowered less than 40mm. Eg are they more stiff as well as being shorter??