US Model Auto antenna removal

[Lapping]

Could someone please provide detail on the method associated with the removal and installation of an original auto Antenna. I own one of the last 500 71 280 SL 4 spd manuals built and I am hoping that I can get the antenna serviced and fully operational again. In essence the antenna still operates but only rises to half of its maximum height suggesting the internal plastic drive is compromised - advice and service guidance would be greatly appreciated. Cheers Nigel (Australia) 

[66andBlue]

Your antenna may function correctly, that is, if it has the "length limitation" stop switch built in someone may have adjusted that to its current length. Without knowing the exact manufacturer/model number it is difficult to comment more.
You might want to read this discussion why this could be the case:
https://www.sl113.org/forums/index.php?topic=13698.msg93011#msg93011

Also consult this page: https://www.sl113.org/wiki/Electrical/Antenna

[Shvegel]

The original Hirschman Auta 6000D or U antenna in working condition is fairly rare.  First and foremost the goal is to not turn a working antenna into a non working one.
Here is what I suggest:

Look at the base of the antenna and see if there is a raised "H" logo inside a raised shield.  This will identify it as a Hirschman antenna which would be the correct manufacturer. 

Remove the right front tire and at the rear of the wheel opening there ia a panel that is installed with hex head screws.  Remove that panel and take a look at the motor housing.  Most of our cars were fitted with a Hirschman Auta 6000D or 6000U.  The motor housing is all aluminum without any black plastic.  If your housing is all aluminum STOP.  Put it back together and start trying to find a mast for a Hirschman Auta 6000D or 6000u.  The "D"or "U" is very important since they carried on into the E series and F series etc and my understanding is the masts are not interchangeable.

If you are able to locate a mast only then would I try to remove the antenna from the car.  You are dealing with an aluminum housing  that has been in the weather for almost 50 years and the chances of destroying the threads on the housing are real.  Be gentle.  The antenna is removed by removing the wheel and panel and unscrewing the lower bracket from the car and the upper nut at the top where it meets the fender.   The fat antenna wire should unscrew from the assembly and the other wires might have to be chased under the instrument panel to disconnect them.

[66andBlue]

Hmm, I did not know that you can ahve access to the antenna from the wheel well! 
Are you sure?
I posted this photo in a another thread that describes the issues with antenna installation.
AFAIK, the antenna sits behind the right panel in the passenger foot well.

https://www.sl113.org/forums/index.php?topic=24747.msg177024#msg177024

[Shvegel]

Hmmm.  Mine was a manual but it was outside the cowl.  I assumed the electric ones were as well.  Thanks for the correction.  As a side note I am glad I supplied my body man with the correct measurements for the hole when he changed the fender.

[66andBlue]

The correct location for the antenna is the same for automatic and manual. On the original outer fender there is mark visible on the inside and the inner fender has already a factory pre-cut hole. See: https://www.sl113.org/wiki/Electrical/Antenna