Bilstein B8 front strut alignment

T

Tobias R

Member
 Sweden
Hi,
I recently bought a Z4 3.0 2003, and have performed some necessary maintenance this winter. Yesterday I fitted new Bilstein B8 front struts and noticed an issue during the assembly.

On the original struts there are alignment pins to position the struts, but these are missing on the B8's. So I used the printed line on the sticker on the strut, but doing so the alignment of the B8's aren't the same as the original. There's a notch in the lower spring plate, that on the originals are rotated slightly towards the back of the car. Also the bracket for the sway bar is rotated slightly inwards. With the B8's the notch in the spring plate is sitting more or less perpendicular to the center line of the car, and the bracket for the sway bar is parallell to the center line. So my feeling is that both struts should be rotated 20-30 degrees backwards.

Has anyone experienced the same issue, and is the alignment of the strut that important? Or can I drive the car like this without any issues? I assume Bilstein has put the orientation marks there for a reason, but on the other hand so has BMW.

I didn't take any pictures before unfortunately, but this is how it looks assembled now.

IMG_1607.jpeg
 
If the bottom end is properly aligned with the two rivet heads down in the slit in the hub then there is no other way for the strut to sit.
The top mount revolves anyway so doesn’t matter.
The issue is not the strut at all, it is the lack of a camber pin in the top mount. You will need an alignment done anyway so that isn’t an issue.
 
When he says alignment pins is he meaning those rivet heads?

Are you sure they are the right struts for your car? Can you share the part number with us?

Just for my own OCD you'd imagine that they would have made the strut so the Bilstein sticker is viewable when installed?
 
I have a sneaking feeling the b8s don’t have the 2 pins to locate in the groove

I may be wrong
 
bigwinn said:
I have a sneaking feeling the b8s don’t have the 2 pins to locate in the groove

I may be wrong
Click to expand...
The clamping bolt is supposed to pass between those two pins so the strut can't lift out.
Sounds a bit dubious to just rely on the clamping force?
I accept the pins aren't exactly massive, but every little helps.
Put me right off having those if that's the case.
 
Yes, with alignment pins I meant the two rivets. They aren’t present on the Bilsteins. I don’t have the part number for the struts at hand right now, but I have double checked the part numbers with Bilstein before so they shall be the correct ones. From the YouTube videos I’ve watched to prepare myself all Bilstein struts have looked like mine, without the rivets.

And when comparing the both struts they look identical in shape to the originals, except from the missing rivet. Are those rivets really meant to secure the strut from being pulled out? I could remove the strut without removing the pinch bolt.
 
Tobias R said:
Yes, with alignment pins I meant the two rivets. They aren’t present on the Bilsteins. I don’t have the part number for the struts at hand right now, but I have double checked the part numbers with Bilstein before so they shall be the correct ones. From the YouTube videos I’ve watched to prepare myself all Bilstein struts have looked like mine, without the rivets.

And when comparing the both struts they look identical in shape to the originals, except from the missing rivet. Are those rivets really meant to secure the strut from being pulled out? I could remove the strut without removing the pinch bolt.
Click to expand...
If the pinch bolt is torqued up correctly I'm guessing it should hold it in place. But if you buy Bilstein B4, or Sachs (the two I've used before) they have those rivets.
 
To add to this, all I can suggest is that I would expect the ARB drop link to have both upper and lower ball joints more or less centred with the wheels in the straight ahead position.
 
enuff_zed said:
To add to this, all I can suggest is that I would expect the ARB drop link to have both upper and lower ball joints more or less centred with the wheels in the straight ahead position.
Click to expand...
Maybe the B6s and B8s don´t have these rivets due to the damper unit being of upside down design, I don´t know.. Anyway, I will try my best to have the drop link bracket oriented as on the original struts. To have the drop link perfectly in line with the wheel isn´t possible since the bracket is on the back side, same as on the original struts. But rotating the strut somewhat will bring it slightly closer to the wheel center at least.

What did you mean with that the top mount is lacking the camber pin? The new top mounts have the same design as the original, with the locating pin. But I will do a full wheel alignment once the car is back on the road for sure.

If anyone wants to double check the struts the part numbers are 35-124115 and 35-124122.

Thanks!
 
Tobias R said:
Maybe the B6s and B8s don´t have these rivets due to the damper unit being of upside down design, I don´t know.. Anyway, I will try my best to have the drop link bracket oriented as on the original struts. To have the drop link perfectly in line with the wheel isn´t possible since the bracket is on the back side, same as on the original struts. But rotating the strut somewhat will bring it slightly closer to the wheel center at least.

What did you mean with that the top mount is lacking the camber pin? The new top mounts have the same design as the original, with the locating pin. But I will do a full wheel alignment once the car is back on the road for sure.

If anyone wants to double check the struts the part numbers are 35-124115 and 35-124122.

Thanks!
Click to expand...
Forget my comment about the top mounts. That was my misunderstanding of your issue.
Regarding the drop link: align the top and bottom ball joints so they are central and when the strut is correctly aligned they should fit without any adjustment.
 
Alright! I have now adjusted the struts so the drop links align better. Fingers crossed that the struts won’t pull out of the knuckles if I accidentally jump a crest 😀
 
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