jjhoneck

Today perfectly illustrates the joys of owning a classic car. Sometimes the simplest job trips you up and will turn into a major task.

Since buying the Corvette, the driver's side mirror has flopped around in the wind. I tried putting a little glue in the ball joint -- nope, no difference.

Fine, I ordered a new one. It is held on with a single allen screw. A 3-minute job to swap, easy peasey.

So, I take off the old mirror, leaving the mounting base attached to the car. I look at that old base and decide that it's corroded a bit and I should put the new part on.

Fine, 2 more screws. No biggie.

I put the new part on. The new mirror doesn't fit on the base as tightly as I would like. It actually fits the old base better. So, I take it over to the bench grinder, and wire brush all the corrosion off, and hit it with a coat of Corrosion X for good measure.

I go to put the old base back on the car, and whoops -- the front screw won't tighten. WTF? It's stripped.

There is supposed to be a backing plate behind the fiberglass. There is not. WTF?

So, the hole is wallered out. The idiots had mounted the mirror to the car solely by screwing sheet metal screws into the fiberglass! This is not the way the factory did it. There is no backing plate. This is NOT good.

What to do? I can go to one screw size up -- but it's still only going to be screwed into thin fiberglass. Not a good idea. So, it's time to take the door apart and get at the backside. What fun!

Digging out the Service Manual, I find all the screws, and use my special tools to take the window crank and door lock off. All that's holding the door panel on are the clips around the outer edge.

There's one. There's two. There's three. *pink!* The fourth one snaps off. It's 45 years old, and the thin metal just decided to....let go. Argh.

But, the panel is off. I go behind the mirror, ready to put washer and nuts on -- only to find a solid steel channel brace directly behind that spot on the door. There is NO WAY to get at the back side of the fiberglass. Double argh!

I know what I need to attach it from the front -- basically a drywall anchor for fiberglass -- but I don't know what they're called. They go in the hole from the front, they're metal, and they expand behind the hole, giving something for the screw to thread into. Off we go to O'Reilly's Auto Parts, who, of course, have no idea what I'm talking about and cannot help.

Then, it's off to Lowes. Nope, they don't have it either. Back to the hangar we go.

So, I jump on the internet and order the stupid side panel clip from a Corvette specialty shop. $5 bucks for two of them. Not terrible, for an 18 cent part.

Then, I jump on this forum and beg for help. The answer comes quickly. Apparently there are these things called "well nuts" that are basically lengths of rubber hose with a brass nut inside. You stick them in the hole, like drywall anchors for thin fiberglass, screw in the screw, and it expands behind the fiberglass. I will need to enlarge the holes and put those things in, and THEN I can attach the mirror.

Unfortunately, it's Saturday night, and no hardware stores are open. Triple argh.

So, my "3 minute job" before heading off to the car show in Corpus ended up taking all night, and was fruitless. Worse, I broke another part in the process.

The joys of owning old cars!

Stupid, stupid, STUPID.

Here are a couple of pix.

No backing plate! Argh. The inside of the door. Looks like Rube Goldberg was here.

Mr D.

Found this,

https://www.volvette.com/MI24A.html

Pretty sure my 71 has a backing plate

jjhoneck

Looking at the inside of my door -- and seeing that red paint -- my guess is that this is NOT the original door on the car. The car has always been yellow, from the factory.

I know the previous owner had the car resprayed in 2010ish. My guess is this door must have been replaced at that time -- which would also explain the amateurish mirror installation job.

I love antiques. My '52 Chieftain and '80 El Camino are the same way.

Alan 71

Hi,
The original left side doors all had the backing plate for the mirror.
I think you'll be disappointed with 'well nuts'. They hold the mirror tight at first, but loosen as time goes by.
I think you may find the the 'moly' bolts you describe crush the fiberglass and will also also loosen as time goes by.
Are the holes in the right place? They appear to be a little low.
The holes were typically 1 1/2" from the top edge of the door.
Regards,
Alan

Mr D.

My hole are 1 1/2" down on my 71 just as Alan stated, you can see the rivets holding the backing plate.

jjhoneck

Boy, that would be nice.

Of course, there's easy no way to install that now.

Mr D.

If you can't buy or find a backing plate it would not be difficult to make one

jjhoneck

All of the right hand mirrors (which were dealer installed) were installed using well-nuts. Has there been a problem with them?
--
Jay

Mr D.

Can you see the holes looking inside the door, maybe that opening in the top

Mr D.

I just searched all the normal vendors and don't see this bracket anywhere. The attached picture is for a C2 to give you a idea of what to make or find.

Doesn't need to be riveted if you can get to the backside to install the outer bracket and screws.

Alan 71

Hi Jay,
When the right side mirror became available as a dealer installed option (73?) it was installed with well nuts.
People often mention that the right side mirror tends to loosen over time.
Regards,
Alan

jjhoneck

The backside has a steel reinforcement beam covering it. You can't get to those holes at all.

​​​​​​ I've read that some guys have drilled access holes in that beam to get at the backside of the fiberglass, but that strikes me as a very bad idea. That beam appears to be one of the primary strengtheners for the door.

Another guy says there is some way to fish a backing plate through that steel beam/channel to the backside of the fiberglass with a wire, but that sounds like an enormous PIA, and I can't picture how you would hold it still to (blindly) catch the screws.

So, I just bought an assortment of well nuts. Later today, I will give it a whirl.

Considering this mirror was attached with NO backing at all, I think a well nut is a big step up.

jjhoneck

Well, after 2 days of futzing around, I have achieved "mirror". lol

I drilled out the front hole with my unibit, dropped my Ace Hardware well nut in -- and it worked perfectly.

Then, although it wasn't yet stripped, I figured it soon would be, so I started drilling the back hole -- and hit metal. The back hole had a proper backing plate!

So the new mirror is held on with one well nut, and one proper mounting screw, which makes me feel better. It feels quite stout, and I at last have a working sideview mirror.

Thanks for all the helpful advice, both here and on my other thread.
--
Jay

sunflower 1972

Glad you got it fixed. And I REALLY like the color of your C3!