Suspension Question

I have my car up on jacks right now with the wheels off and I was looking at the the front wheel hub, and it has three connections, one on the control arm, one on the rack and pinion, and then one on the strut, but it's just attached to the strut with a collar. Like the strut comes down as a 2-3" tube and then the hub just has a collar that tightens around it. So my question is is that adjustable so you can adjust your ride height or is that something that you shouldn't touch? Btw I have the sports package if that makes any difference.

lol no. don't touch that.

btw, that piece you're referring to is the kingpin or spindle. not hub. the hub is what your rotor mounts to and includes the wheel bearing. the hub presses onto the spindle.

Yeah I was trying to think of the name but I just couldn't remember. lol. And what does that do then? Why is it like that?

it serves as the backbone for your front suspension/steering. holds the strut in place.

Yeah I know that, but why is it a collar and not a more solid connection? Like I know I shouldn't touch it because it would probably throw off my handling but it looks like I could just loosen the collar and slide it up an inch, then retighten it. Is it like that so BMW could calibrate the suspension at the factory or something?

it doesn't mean anything. it's just where your strut sits.
if you raised your strut and tried to retighten it it wouldn't hold it. and it would be extremely unsafe. the strut actually has a little lip on it. so it's resting on the lip of the collar.
don't touch it.

Originally Posted by semismart

Yeah I know that, but why is it a collar and not a more solid connection? Like I know I shouldn't touch it because it would probably throw off my handling but it looks like I could just loosen the collar and slide it up an inch, then retighten it. Is it like that so BMW could calibrate the suspension at the factory or something?

No

only way to lower is with lowering springs or coilovers

The shock wont go any lower into the collar... Even if you try hard

Oh ok, I wasn't planning on lowering it, I scrape as it is with the sports suspension, I was just wondering. Thanks

The strut only goes into the collar one depth, and that is controlled by a tiny tip on the side of the strut that won't slide into the collar any more.
And this depth does not control ride height. Shocks don't hold the car in the position it sits. The springs do that.
If you were to be able to adjust the collar up or down, the ride height would not change. But you'd be messing with the travel extremes of the shock, and potentially set things up to do permanent damage to the shocks (struts).

Alright, I'll make sure not to touch them

Originally Posted by Stinger9

The strut only goes into the collar one depth, and that is controlled by a tiny tip on the side of the strut that won't slide into the collar any more.
And this depth does not control ride height. Shocks don't hold the car in the position it sits. The springs do that.
If you were to be able to adjust the collar up or down, the ride height would not change. But you'd be messing with the travel extremes of the shock, and potentially set things up to do permanent damage to the shocks (struts).

Not true!

Your detailed refutal of the facts is well expressed.

Originally Posted by hummer

Not true!

How is that not true?

If you raise the strut upward say one inch in the pinch bolt area, the strut, spring and the car will rise up 1 inch with it!

I experimented with this for a night or so. What I found was, the two little "nipples" on the strut body are primarily used to orientate the strut to the right geometric location, in reference to the sway bar end links to keep them parallel with the strut. If you were to raise the strut up far enough out to allow the nipples to be out of the collar the strut would twist , causing the sway bar end link to be out of geometric alignment, causing things that should not touch to touch or to bind. I knocked off the two nipples, on an old strut and it had no effect on where the strut set in the collar. I did not put a micrometer or measure the interior diameter of the collar from top to bottom, but I am pretty sure it is tapered along with the bottom of the strut to allow it only to go so far. I am sure if you could lower the strut into the collar at your own desired level, every one would be subscribing to a post about "how the lower control arm was destroyed", when the strut bottomed out onto the lower control arm during travel of suspension. Just my observation.

Die feinen Ingenieure bei BMW denken schneller als wir!

Originally Posted by sfcjetjr

Die feinen Ingenieure bei BMW denken schneller als wir!

And your point being........

Sure, we didn't design the car, but lacking one of those engineers on this board with us, we do our best. And sometimes better vis-à-vis KONI or Stewart.

Originally Posted by hummer

If you raise the strut upward say one inch in the pinch bolt area, the strut, spring and the car will rise up 1 inch with it!

True because the geometry of the strut is such that the position in the strut collar also determines the geometry of the bottom perch of the spring relative to the axle.

Big mistake to position this anywhere but fully seated tho.