135 Coilover Rattle

[mimarcos]

Hi all! Relatively new to 1addicts. Wound up buying a 2011 135i with some modifications. Among them were ISC N1 (track-valved) coilovers. I have a bit of a dilemma...

It's been making a rattle. Almost like a seat belt buckle rattling against the B-pillar if the tensioner is a little loose. Earlier this week, I identified what the sound was: the top mounts of the rear shocks are a little loose.

I don't believe the OEM shocks are setup like this, but to torque down the OEM nut on these ISC shocks, you are intended to use a hex key in the threaded rod sticking up, while torquing the nut down.

My problem that the hex keyway at the top of the threaded rod (pictures here in Google Photos). Like, completely. I've tried a 5mm key and it spins freely. 6mm doesn't fit. I even thought maybe I could get a Torx it in there but not luck with... T40 and T45 I think.

Anyways. I need to either:

• Tighten, with the ability to loosen/remove in the future
• Loosen to remove and buy new shocks while I'm at it (about $250 total)

Anyways. I'm looking for methods to enable the options above. Here's what I've got so far:

• Cut a slot in the threaded rod for a screwdriver. I reeeally don't like this idea. There's not a ton of material and a decent amount of torque I need to add to the nut.
• Drop a torx bolt in with some JBWeld to add a permanent socket attachment. Also reeeeeallly don't like this approach since it means I wouldn't be able to adjust damping (on full soft the car is still really firm, but I'm trying to tech this out for moderate HPDE duty so adjustability would be nice).
• Use duct tape wrapped around the very top of the struts piston rod, use vocegrips to hold it, and try to torque the nut without spinning the piston or using the keyway. I like this the most, but am unsure of the potential for damage

Not a lot of space to work with on the top, either, which makes this a little annoying.

Anyways, thanks for any support! Loving the e82 platform and can't wait to see what it's capable of!

[HP Autosport]

Hit it with an impact gun/air or electric ratchet and stop as soon as the nut has been fully seated and tight.