Ken, the strut already has an aircraft nut in your pic. It won't back out.

 

Correct, the nut is easily accessible. I used a box-end offset wrench (22mm) to clear the opening in the top of the fender. It is an aircraft nut. I left a message a few weeks ago with Bilstein regarding the recommended torque but they never responded. Actually, since that bearing and top mount hardware is from the original factory strut, the torque should be the same as the factory struts. Anybody know what that is?

 

I couldn't find an instruction manual. You might try calling Ground Control in CA. They are suspension experts and could provide some guidance.

 

We've now replaced the top bearings, front trailing arms, fore/aft, and inner tie rods.

Rattle /clunk persists.
For 4 1/2 years this has not been an issue on this car.......more than frustrating right now.

 

I had the same issue, my mechanic installed thrust washers and the problem went away