Correct Horn Fasteners

[sixt9x33rs]

The AIM is not real clear (to me anyway) regarding the type of fastener used to hold the horn to the latch assembly. I went with the 9780422 fastener as shown in the AMK catalog. This fastener is widely used on the radiator support and elsewhere regarding sheetmetal. But while scavaging the junk yard yesterday I ran across two Impalas, one a 67 and one a 68. Both examples were very much in tact. I noticed that both fasteners holding the horns to the car were 9/16" AF with a captured washer with small serrations on the inside of the washer. These fasteners were zinc or cadmium covered not black phosphate like the 9780422 fastener. The zinc fastener has the pointed end like the previous mentioned fastener and was also .75"...I think. Anyway if someone knows the correct fastener I would like to see a picture.

Thanks,

Lawrence

[KevinW]

I am pretty sure the serrated ones are correct for 69 at least.  The horn grounds through that bolt and the serrations had to bite past the paint to bare metal.

[Mike S]

Hello,

 I checked mine on a 67 LOS (original) and NOR (restored) horn assemblies and they both use the pointed cad plated serrated fasteners. That is for 67 though and I would assume that would follow through to 69 and beyond being a horn is a safety item which I believe is the reason they are plated and serrated.

Merry Christmas!
Mike

[sixt9x33rs]

Thanks guys!

Merry Christmas

Lawrence

[m22mike]

Lawrence
 I believe your observation on the 67 and 68 cars is spot on. I believe the zinc plated horn bolts were superceded to dark phosphate around the early run of  69 Cheverolets. That has just been my observation from looking at unmolested cars.
Most 69's hand very few zinc plated fasteners under the hood. Exceptions being some of the sheetmetal screws like VR, horn relay, ground straps, and washer bottle bracket hold down screws.
 I am not at home now and can not give you the page #'s and PN's now. But in my two coppies of the 69 Camaro Assembly manual where it shows one of the horns and bolt detail, there is a revision to that bolt, dated I believe 10/68. In the lower revision box on that page it states the # of the zinc fastener and the word "Was". I believe on Camaros they started using the same dark phosphate bolt that holds the lower hood latch to the core support and header. Not serated, and with a captured washer.
 I had asked Steve Shauger this same question awhile back concerning horn bolts on 69 Camaros. I believe he told me that he had seen Zinc horn bolts on some early 69's only.
 Always take the time to soak in all the detail stuff on unrestored cars, not just Camaros.

Mike

[JohnZ]

But in my two coppies of the 69 Camaro Assembly manual where it shows one of the horns and bolt detail, there is a revision to that bolt, dated I believe 10/68. In the lower revision box on that page it states the # of the zinc fastener and the word "Was". I believe on Camaros they started using the same dark phosphate bolt that holds the lower hood latch to the core support and header. Not serated, and with a captured washer.

That's correct - my original 02D car has the same bolts on the horns that attach the hood latch to the front of the radiator support.

[sixt9x33rs]

But in my two coppies of the 69 Camaro Assembly manual where it shows one of the horns and bolt detail, there is a revision to that bolt, dated I believe 10/68. In the lower revision box on that page it states the # of the zinc fastener and the word "Was". I believe on Camaros they started using the same dark phosphate bolt that holds the lower hood latch to the core support and header. Not serated, and with a captured washer.

John aren't the Fasteners that hold the hood latch assembly to the radiator support all the same? All four Fasteners are the same right?
That's correct - my original 02D car has the same bolts on the horns that attach the hood latch to the front of the radiator support.

[Steve Shauger]

Lawrence
 I believe your observation on the 67 and 68 cars is spot on. I believe the zinc plated horn bolts were superceded to dark phosphate around the early run of  69 Cheverolets. That has just been my observation from looking at unmolested cars.
Most 69's hand very few zinc plated fasteners under the hood. Exceptions being some of the sheetmetal screws like VR, horn relay, ground straps, and washer bottle bracket hold down screws.
 I am not at home now and can not give you the page #'s and PN's now. But in my two coppies of the 69 Camaro Assembly manual where it shows one of the horns and bolt detail, there is a revision to that bolt, dated I believe 10/68. In the lower revision box on that page it states the # of the zinc fastener and the word "Was". I believe on Camaros they started using the same dark phosphate bolt that holds the lower hood latch to the core support and header. Not serated, and with a captured washer.
 I had asked Steve Shauger this same question awhile back concerning horn bolts on 69 Camaros. I believe he told me that he had seen Zinc horn bolts on some early 69's only.
 Always take the time to soak in all the detail stuff on unrestored cars, not just Camaros.

Mike

Hey Mike, I just inspected a 10C of 68 car and it had the zinc plated horn bolts with serated washer.

[m22mike]

That's neat, thanks Steve.

Mike

[JohnZ]

But in my two coppies of the 69 Camaro Assembly manual where it shows one of the horns and bolt detail, there is a revision to that bolt, dated I believe 10/68. In the lower revision box on that page it states the # of the zinc fastener and the word "Was". I believe on Camaros they started using the same dark phosphate bolt that holds the lower hood latch to the core support and header. Not serated, and with a captured washer.

John aren't the Fasteners that hold the hood latch assembly to the radiator support all the same? All four Fasteners are the same right?
That's correct - my original 02D car has the same bolts on the horns that attach the hood latch to the front of the radiator support.

All of the hood latch support bolts are #3960314, including the bolt for the R.H. horn; the L.H. horn used #3846202. All are black phosphate.

[Steve Shauger]

But in my two coppies of the 69 Camaro Assembly manual where it shows one of the horns and bolt detail, there is a revision to that bolt, dated I believe 10/68. In the lower revision box on that page it states the # of the zinc fastener and the word "Was". I believe on Camaros they started using the same dark phosphate bolt that holds the lower hood latch to the core support and header. Not serated, and with a captured washer.

John aren't the Fasteners that hold the hood latch assembly to the radiator support all the same? All four Fasteners are the same right?
That's correct - my original 02D car has the same bolts on the horns that attach the hood latch to the front of the radiator support.

All of the hood latch support bolts are #3960314, including the bolt for the R.H. horn; the L.H. horn used #3846202. All are black phosphate.

I respectfully disagree, because I have 5 documented cars (4 unrestored and one needing restoration), all produced from 9B to 10C (of 68) that were built with the horns secured with zinc plated bolts with serrated washers. My point to Mike was that 10c is the lastest built car I have found . Just an FYI, but all examples were built at Norwood.

[68camaroz28]

This is one of the horn bolts on our 01B 68 Camaro and it is zinc.

[Steve Shauger]

Chick, that is what I have seen on the examples I referenced in my previous post. The head marking is typical of what I have seen on the zinc bolts. Thanks for posting.

[IZRSSS]

Steve/Chick - Is this the same horn fastener that was used for 69's or at least early build 69's? This is the same one I have on mine.

[69Z28-RS]

I've been following these threads on fasteners pretty carefully because my original '69 Z28/RS (late 09C build) was apparently in a minor front end fender bender early in it's life (not the greatest repair, as I believe all the original fasteners were put back on, but not *necessarily* in the same locations they came from...     I know it was in an accident because when I purchased it in '76, the lower valence had a GM pn sticker on it's backside, and there's a small amount of fbody iller in the front portion of the hood.   It's difficult for any of us to know (unless we owned our cars from new) and even then we might have even *forgotten* about minor repairs performed 40 yrs ago... so going by what is on our cars is not as *robust* a method as what the AIM shows...

[JohnZ]

All of the hood latch support bolts are #3960314, including the bolt for the R.H. horn; the L.H. horn used #3846202. All are black phosphate.

I respectfully disagree, because I have 5 documented cars (4 unrestored and one needing restoration), all produced from 9B to 10C (of 68) that were built with the horns secured with zinc plated bolts with serrated washers. My point to Mike was that 10c is the lastest built car I have found . Just an FYI, but all examples were built at Norwood.

I don't disagree - the horn bolts may have been changed under a local Engineering deviation to the zinc variety to improve grounding, but it's unusual that the A.I.M. sheet was never revised to reflect the change if it was indeed permanent - it shows both horn bolts as black phosphate, although different part numbers.

[IZRSSS]

Each of my horns has a different fastener...go figure? One exactly like Chicks with an S on the head (Zinc), and this one with an anchor on the head and I'm pretty sure... is black phosphate.
 

[68camaroz28]

Marty, that anchor bolt sure looks like a zinc coating under the captured washer... When was your Camaro built?

[IZRSSS]

12A LA Build...
Is a Black Phosphate finish baked into the metal? If so, you are probably correct. If it is BP It shouldn't have lost its color right? 

[68camaroz28]

12A LA Build...
Is a Black Phosphate finish baked into the metal? If so, you are probably correct. If it is BP It shouldn't have lost its color right? 

Phosphate is a chemical process and not a baked on process. No I do not think it should have lost its color like the thread and underside show if it was a phosphate bolt originally. I have taken rusted bolts and upon removing the rust (evaporust) it is nomally quite evident to still see the dark gray phosphate appearance. Your bolt Marty appears to have been coated with something while it was in place (threaded in) hence the upper portion of thread and underside so zinc looking. Maybe someone sprayed some coating on it while it was threaded into something other than the car? Just my thoughts!?!?

[IZRSSS]

Maybe someone sprayed some coating on it while it was threaded into something other than the car? Just my thoughts!?!?

I think your probably spot on...I think I'll hire you to find my cars owner...

[1968 Z28]

12A LA Build...
Is a Black Phosphate finish baked into the metal? If so, you are probably correct. If it is BP It shouldn't have lost its color right?  

Phosphate is a chemical process and not a baked on process. No I do not think it should have lost its color like the thread and underside show if it was a phosphate bolt originally. I have taken rusted bolts and upon removing the rust (evaporust) it is nomally quite evident to still see the dark gray phosphate appearance. Your bolt Marty appears to have been coated with something while it was in place (threaded in) hence the upper portion of thread and underside so zinc looking. Maybe someone sprayed some coating on it while it was threaded into something other than the car? Just my thoughts!?!?

Hi Chick....A word on EvapoRust.  Leave the metal in long enough and the EvapoRust will deposit its own layer of phosphate.  I have taken bolts and scrubbed and buffed them until they were down to the bare metal....put them back into the EvapoRust, and leave them there for awhile and they will come out with a back coating on them.

In some of their literature they even state that this will happen.

[69Z28-RS]

I've noticed the same thing..  chemically, I doubt there's a huge difference in the makeup of 'Evaporust' and 'the phosphating' solution sold by Plametto enterprises....