Help! Can't get the chrome nut off my antenna to replace the mast!

[imautoparts]

1995 C220, electric antenna in rear quarter panel.

When I use my 13mm wrench to loosen the external chrome nut (the one with a hole in the middle that secures the mast in place) it just spins - doesn't come out of the fender trim piece at all. I tried holding the little plastic collar just below the nut with a pair of needle-nose, but it just spins and stays in place.

I reached around into the fender and can grip the antenna body itself, but again - no movement of the nut, it just spins and spins.

I'm out of thoughts on this one. Anybody have any ideas?

[Vetruck]

Did you unbolt the entire power atnenna assembly yet? I would just ry and remove the two bolts inside the truck and put a little downward and side tension on the unit as you try to remove the top nut. It may be stripped and just pull stright off with a little force

[John Jones Jr.]

I've had this problem before on other cars including a 190E. From what I've seen if the exterior nut won't undo it's time to get a new aerial complete as even genuine replacement aerial masts don't seem to come with a new nut.