Quote:
Originally Posted by mindspin311
How do those 3 holes orient with the car? Which is facing forward, etc?
First thought is the surface just isn't flat. From there, the strut mount wasn't torqued down in any certain way, and left a gap in at your top right mount hole. The clamp force on the other 2 is so strong that the 3rd torqued out and everything seemed fine per torque values, but really there is a gap, evidence by less gasket transfer.
In reality, the mount is pivoting on that axis you called out when you apply near 1000lbs on that one corner at certain points.
Or, is the strut mount not flat, somehow it's bowed out and creates that axis?
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Here's a diagram. A sharp compression impact will cause the wheel to move rearward and inboard in an arc centered approximately about the inboard control arm bushing. The arc is exaggerated on my diagram, but a large enough impact could align the load with the direction that would allow some play at the upper mount.
I'd be pretty surprised if BMW screwed this joint up this royally, but I'm not seeing anything else obvious. This is obviously why they went to a 5-bolt mount, but hearing from some 2018 owners in here, it's clear that it didn't solve the issue and there's still some variation or clamp load sensitivity that there shouldn't be.
As I said, next step is to bolt everything back together as cleanly as possible. I'm going to tighten in multiple stages to try to get even clamp load, but I'm going to do it in an order that ensures that if there
is any unevenness due to bolt torque, it's in a direction that opposes the wheel loads.
