Antenna won't go up in 1980 450sl

[banjobob]

I hear the motor working but the antenna won't go up, unless I help it. It seems it gets stuck the first 1/4 inch and then its fine. I took the antenna out and cleaned it at best as I could with wd-40, but still the same. When I operate it in my hands I don't feel it sticking. It seems like whatever holds onto the white cord and pushes the antenna up just slips and does not have enough friction to get it started. But like I said, I little help for the first 1/4 inch and its fine the rest of the way up. Does the mast need replacing or is it something else. Any help or advice would be greatly appreciated. Thanks

is it the original antenna with the aluminum housing? if it is when you open it, tighten the big nut, that will tighten the clutch, don't go too much as this may damage the unit, have you tried installing a new mast?