My power antenna in the 300D stopped working today. It is stuck in the up position and I cannot force it down, doing so would break it. I can hear the motor running to crank it up and down when the radio is operated but it doesn't move. I have done a search but I don't quite get what people are talking about in the postings. Do I have to replace the "mast" to fix this? I assume the mast is the actual antenna part I see coming up out of the car? Or is there a different/separate drive piece, the toothed or smooth part refered to in the posts? Just a little confused and would like to know a little more before tearing it apart. Thanks, RT

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84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K

Loosen the nut at the base of the mast. Gently pull on the mast. I suspect that the toothed belt is broken on yours. If so it should pull out. The plastic toothed belt runs up inside the mast. When you get your new one put the ant. switch in the up position with the radio on. insert the belt into the hole. For safety sake have someone hold the ant. while you shut the radio off. It should pull everything down into place. Tighten the nut at the base.

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'85 300SD (formerly california emissions)
'08 Chevy Tahoe
'93 Ducati 900 SS
'79 Kawasaki KZ 650
'86 Kawasaki KX 250
'88 Kawasaki KDX200
'71 Hodaka Ace 100
'72 Triumph T100R

If the motor runs but the antenna does not move, it is likely that the plastic "cord" inside the mast has broken. The new mast can be installed without removing the motor assy if you can get all of the original plastic cord out. Sometimes the cord breaks and part of it is left behind. It often will jam when it comes off the reel, as the broken end does not "make the turn" to enter the exit tube. In that case, you usually wind up having to disassemble the motor to remove the broken piece. That is also a good time to clean the drive assy and freshen up the grease on the worm gear and sprocket. But if you can get all of the cord out (the original end should be tapered) then you don't even have to open the trunk. Sometimes internal wear will prevent the new cord from feeding properly. In that case, open the motor assy.