The power antennae on my 79 SD wasn't working right. I disassembled it tonight. Turns out, despite having a drain, moisture has been accumulating in the lower left corner. In that corner is a small spring loaded tensioner pulley which pushes the plastic drive against the drive wheel. Because of the moisture, mine is seized up, causing the problem (I think). Right now I have it soaking in a cup of WD40 but it was seized very tight. I'm not confident it will free up. I doubt the part is available by itself so I'm wondering if anyone has one sitting in the corner of their toolbox that they don't need anymore. The rest of the power antennae looks ok so I hate to have to get a complete replacement.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

I did what you are doing almost a year ago and it is still working. I keep meaning to open it back up and drill a drain hole in that corner. From what i can tell this is a normal problem with these and re lubing should be on be on the regular maintenance list.

__________________
1983 300SD
200000miles

parts units pop up in the classified section from time to time.

I did have some pretty bad moisture issues in mine when I disassembled mine. some PBBlaster and a nylon parts cleaning brush took care of it. then lubed it up, works pretty good now.(at least 90% of the time)

__________________
1984 123.193 372,xxx miles, room for Seven.

1999 Dodge Durango Cummins 4BTAA 47RE 5k lb 4x4 getting 25+mpgs, room for Seven.

The problem with drilling that hole is that water will exit that hole and end up in the trunk rather than accumulating high enough in the antennae box to flow out thru the drain hose tube and out onto the ground.
Was your pulley seized and did it release?

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

False alarm. Bearing freed up after some time in the WD 40.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13