21 Cascadia turning vane

I guess you can take it out and cover holes from nuts with some plastic clips. Check inner side of the door frame.
Guys at dealership told me those stabilizers are for aerodynamics and reducing wind noise.
Check all rubber stripes around door frame and window. Maybe one of them is loose and making this sound. Also check the rubber around windshield.

 

Easiest way is to go to any Freightliner’s parts department and ask them to show you diagram for that area. They will tell you what is holding it.

 

Sawzall

 

My Cascadia whistles in high winds.. The mirror arms are the cause.
Had the window open, on the interstate, into the wind... Tested the theory, put my hand to block airflow on various places...
It was the joint between the vertical mirror section and the horizontal arm section...
No idea how or why, but that's what I discovered

 

Take the whole dam assembly off and go to the old school west coast mirrors... Besides they look better anyway.

 

Tape never lasts...
Cram a piece of card stock in the gap.
It'll get wet and swell, then a sharpie to make it blend in.
Is pretty tacky, but it works, and it's free

 

what is a "turning vane" ??