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Old 09-13-2018   #1
Join Date: Jul 2009
Location: Rocky River Ohio
Posts: 310

GTA Year: 1989
GTA Engine: 350 TPI Automatic
Power antenna repair

I finally got around to repair the power antenna that broke last year. It broke in the full up position and I had to unplug the power from the relay on the passenger side under dash to stop the motor from running. Then, I had to cut a hole in my winter cover when I covered the car! Duct tape repair coming for that.

I read ancient threads on TGO about this repair. Try as I might, I could not get the antenna mast to go down at all. Everything I read said you cannot get the unit out of the fender with the mast up (without bending it).

To get the unit out I removed all of the fasteners from the passenger side ground effect panel, except where it bolts to the front fender on the inside. I removed all of the lower fender bolts, including the brace in front of the wheel and the fasteners for the front ground effect panel. I loosened the fender bolts at the top under the hood. RF wheel was taken off and the back half of the inner fender was unfastened. I luckily did not break any of the plastic push pins.

All this allowed me to pull the fender out about two inches at the bottom. Once I had the top antenna nut off and the inner brace unbolted I was able to slide the unit out. To get the necessary slack in the antenna cable and wires (I did not want to cut the wires, as some have done) I was able to pry out the rubber grommet and pull the wires out of the interior There is a good 18" of extra slack in the antenna cable and I did not have to unplug it from the back of the radio. This allowed me to pull the whole antenna unit lower so the mast would clear the hole.

I had the car up on my 4 post lift. I was able to set the car up at a comfortable working height. I was able to work on the unit next to the car on a small table. Even though the wires are fully disconnected from the car, they are attached the the motor unit and the wires pass through the grommet with the antenna cable and this limits how far you can get it out of the car without unplugging from the radio.

OK, I removed the clips (5) with pliers. One flew across the garage, but I found it. Then you have to drill out 4 hollow rivets and pry the case open. It is sealed with some black RTV type silicone. The plastic cable or wire (whatever you want to call it) that operates the mast was broken near the end that attaches to the gear wheel. This stuff was so stiff and brittle I am really amazed that it worked for 28 years! To get the top of the mast out you have to unscrew the finial at the top of the mast. I used a small vice grip to grip the mast and used a metric socket (don't remember the #) to unscrew the finial. Then you can pull the top mast section out of the tube by pulling on the remnant of the plastic cable. The other two mast sections stay in the tube.

The bottom of the top mast looks like it was crimped to hold the plastic cable. I heated it with a propane torch and pulled it out. At the gear wheel end there is a curved metal tube that is inserted in a slot of the gear wheel. The plastic cable is crimped into this also and was torched out. I cleaned out both the mast and (I'll call it) the gear tube with an appropriate sized drill bit. I straightened out the plastic pieces and measured them and added 3/8" X 2 for where it was inserted into each metal section. I came up with 36". I went to Lowes and bought 48" of 3/32" cable rope at $0.30 per foot. I cut it to length at home with a cut off wheel in a Dremel.

The plan was to solder the cable into the metal parts. I cleaned everything and fluxed. I used rosin core electrical solder and heated the tubes and applied the solder like sweating copper tubing. Seemed like it was going to work. The mast end seemed very secure. The gear end pulled apart. I re-cleaned/fluxed and tried plumbing solder. Still not holding. I decided to crimp this end with electrical pliers in the slot for non-insulated connectors. Seems like it made the same type of crimp that held the plastic original cable. Grabbed it with two pair of pliers and gave it a couple good test tugs - holding tight.

I cleaned the gear wheel and worm gear and lubed with white lithium grease. I rewound the cable onto the gear wheel and inserted the mast into the tube and pushed it out some to reattach the finial. Some threads said you need a third hand to hold the wound cable in place while you try to install the cover, but I was able to do this without help.

Before I went any further I just used some clamps to hold the two halves together, so I could test it before completing reassmbley. I used a 12V power supply (I got it at Radio Shack for $10.00 when they went out of business) and applied power to the white (-) and green (+) terminals. Viola! The antenna rose. But, it would not go back down. The Radio Shack unit did not have enough power to hit the limit switch, I guess. So, I fished the wire back into the car and plugged it into the relay and the mast went up and down smoothly several times. Nice.

I reinstalled the unit in the fender, fished in the wires and cable, etc. I did not re-fasten any of my other work...yet. Now that the antenna was mounted I tested again. On the second time down, it would not raise again. Crapola. I was getting pretty good at pulling this thing and in ten minutes I had it on the table and open. The cable had pulled out of the mast end, the solder joint did not hold up to 12V car battery power. I crimped this end like I did the gear tube end. However, with the mast end you have to be careful not to deform the end of the mast because it will not slide smoothly inside the middle mast section. Trial and error with a small tack hammer on the vice anvil got it nice and round and sliding smoothly, plus it was very secure after some plier tugging tests. It was reinstalled and I ran it up and down about a dozen times. It's back to its 1989 level of performance. I spent the next hour reinstalling all of the ground effect and fender fasteners and the interior bits.

A couple things: If I did not have the 4 post lift, I would be crippled now. This took me the better part of 1/2 a day, including clean up, etc. I do not have an antenna nut tool. I was going to buy one from Amazon. Then I thought of my snap ring tool with the 90 degree tips. I used these like a spanner wrench, slowly and carefully turning it until I could move it with my fingers. Same thing putting it on. I got it as finger tight as I could, then gave it an extra turn with the snap ring pliers. I lubed the rubber grommet with petroleum jelly and popped it back in. Including tax, I have $1.30 into this repair. I could have done it for under a dollar if I had only bought 36" of cable instead of 48".

Even with the mast down, it would be a tight fit getting the unit in and out without loosening the fender. The extra half hour I spent loosening the fender was well worth it. I tried to remember to take pictures as I went along, but you know how that goes. I do have some and if anyone needs to see something I may have I'll try to post them.
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Old 09-15-2018   #2
87 GTA 305 Auto
Join Date: Feb 2010
Location: Cincinnati Ohio
Posts: 150

Re: Power antenna repair

This has been on my to-do list for a few years also.
I tried getting the nut off without buying a tool but it was too tight and I feared messing it up cosmetically - so getting a tool is my next step.

I didn't realize getting it out from the fender was that much trouble though.
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Old 09-16-2018   #3
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Join Date: Mar 2015
Posts: 280

Re: Power antenna repair

Good work Tony!

I R&R'd mine (died mast down, thank God) with the car on the ground, with the fender on. It's very tight, but do-able. If mine had died mast up, I think I would have had to buy another unit.
1988 Pontiac Trans Am
POCI #72200
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Old 09-18-2018   #4
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Join Date: Sep 2009
Location: Lone Jack, Missouri
Posts: 457

Re: Power antenna repair

Originally Posted by DynoDave View Post
Good work Tony!

I R&R'd mine (died mast down, thank God) with the car on the ground, with the fender on. It's very tight, but do-able. If mine had died mast up, I think I would have had to buy another unit.
Mine crapped out with the mast up years ago. Just clipped the wires to keep it from running constantly until I could work on it. I don't listen to the radio (usually have a cassette in), so I removed the front wheel and inner fender well and got it to the mast down position and when I get free time to repair it, I'll have plenty of info to get the job done.

1991 Bright Red GTA...1st place Light Modified Class 2009 & 2014 TA Nationals
41,xxx original miles as of 4/18
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