Wonder if the mechanism, guide, or other internal part has worn or gotten gummed up causing the early failure, and it's not due to a lower quality of the replacement part.

My replacement job failed almost instantly after I installed the Miata antenna mast (which looked to fit perfectly). Now the antenna can be pulled up or down by hand easily, so I guess the rack is disconnected from the gear somehow. Or maybe I have just forgotten how to assemble it correctly the second time! Maybe one of these days I'll tear into it again. Hate the trim disassembly process. Way too tedious. :(

I did mine in 2011. It's still working, but my FD rarely goes out in bad weather, so things don't get mucked up as much as they would if I did.

I know the whole unit was changed over the years, the one in my '02 looks quite different to what was fitted to my '93. Wonder if they still suffer from the same issues.

Just had a complete overhaul on our '94; new engine, new '99 spec turbos, new motor mounts, new OEM wiring, etc, etc. By the time the R-12 was recharged, total came to over $13K. Now the ONLY thing wrong with the car is that stupid power antenna. (See my post #27.)

So did I do something wrong with my repair? IIRC, the nylon gear strip did NOT wrap completely around the gear... should it? Are there any instructions anywhere for a DIY disassembly/reassembly, or am I on my own (again)?

Here are instructions for the FC, basically the same

86-92 Antenna Mast

Thanks much, these are the first instructions I have seen. When I "fixed" this twice before, I rolled up the nylon gear into the reel while the assembly was apart. i'll try it according to these instructions this time!

Yeah, the FSM describes in detail how to do it. Of course, the first time I did this I hadn't read the FSM, lol! Second time, pffft...painless and ridiculously easy.

The problem with the manual is that the FSM says nothing about what to do if the mast breaks, leaving part of it inside the assembly. The assembly must be disassembled to get the broken piece out before the new mast can replace the broken one. Once apart, I guess it can be reassembled without the nylon rack inserted. I didn't know that, until after reading the replies in this thread.

When I replaced mine seems like I had to remove an inch or two of broken teeth. IIRC while apart I put just a pinch of tacky grease on the appropriate areas.

Well if anyone doesnt wanna go through the hassle, I have a complete antenna assembly I pull out of my car

Those Mazdatrix instructions are good. I used them on my FC.

I have my original antenna installed. Since I switched back from aftermarket headunit to the stock tape deck, the antenna only goes up when I turn on the radio. And since I listen to music on my phone via a bluetooth cassette adapter, the antenna never moves, so it's not likely to break any time soon.

Think about it: you put an aftermarket deck in, and the radio goes on every time you key on (unless the radio is totally turned off). The stock deck only drives the antenna when you specifically turn on the radio.

My old Nakamichi raised and lowered the antennae just like stock (only when the radio was on) but my current BT headunit does just what you describe. I have an unused switch on my console I intend to use to manually raise and lower the antennae on the rare times I listen to radio.

My Nakamichi head unit is smart enough to know when it is anything other then radio to put the antenna down, acts just like stock but has Ipod connection.

Yeah, the Kenwood Excelion head unit I just installed is 'smart' and only raises the antenna when calling for radio.
SHOULD save on the overall wear and tear because I, like many others here from the comments, listen more to sources other than the radio more often than not.

Tore the trunk trim apart and pulled out the antenna assembly (again) yesterday. There is a broken piece from the gear that drives the nylon toothed belt. That decoupled the motor and its gears from the belt and drum. So the motor runs, but nothing happens to the mast.

Wife took a pic with her iPhone; see attached photo. I tried epoxying the broken piece back on; pic was taken after the epoxy had cured. But the first test of the unit broke off the same piece; the bond wasn't strong enough to survive. The mast moves freely up and down by hand, but no power operation. Unless I can devise a permanent fix, "that's all she wrote."

Buy a working used one with an antenna still in it from the classifieds. Run a headunit that doesn't turn on the antenna unless you engage the radio intentionally.

If some company ever makes an adhesive that would join this type of material together permanently, they'd make a fortune.

No problem there; the radio is OEM.
I can visualize a permanent fix: a flat washer-like metal piece with a raised section that screws to the existing gear, but outside of making the thing, I'd have to take the whole bloody trunk trim off again and the car would be down for days. Not happening just after having the engine replaced (for 2 months) in Yoshiya's shop. Maybe someday...

not that this is a solution, but I'm sure there is something online that may help. You might have to do some experimenting...

https://www.masterbond.com/applicati...lon-substrates

ADHESIVES for Nylon

Bonding Nylon | Industrial Adhesives | Polyamide Surface Preparation

nashman69g,

Thanks for the links. I tend to believe that a one-piece stressed part like the driven gear of the power antenna assembly is the only thing that will last through many forward/reverse cycles of the mast. Unless the bonding agent actually "melts" and "re-forms" together the base materials, the bond will not be as strong as the material of the part. Lacking a molded replacement nylon gear for the broken original, I would think a metal part like a large flat washer with a raised portion, screwed to the nylon surface of the gear would be the best solution. Maybe in the future... thanks again!

I know its been a few years since you made this post but thank you -- its near impossible to find these antenna anymore and this is an easy $15 fix! you helped me avoid getting the incompatible "replacement" on eBay!

FischerP, would you please elaborate? Exactly what materials did you use, and what did you do? Thanks!

Hi wstrohm
I purchased a replacement mast (the Miata one indicated above) for the OEM antenna assembly I had saved out of my FD and "re-strung" it. I'm waiting on the insulator to complete the rebuild of the antenna. I cleaned the whole assembly and re-lubricated everything with fresh grease, and all that was needed were some screwdrivers (I did have to solder some leads back on the wires for the plug)

Thanks for replying. I'm guessing you had no broken interior parts... my problem was (is, actually) that, as you can see in my picture in post #41 above, the plastic piece ("Broke off") is missing and I never tore the trunk trim down again to repair it. The mast has to be lifted manually to use the radio.