96 Outer Air Dam Screws

[Pat M.]

Re: 96 Outer Air Dam Screws

No, I am not saying that only the early C4s had the center retainer on the bottom.

The center air dam aluminum retainer goes on the bottom UNDER the plastic spoiler on ALL C4 CORVETTES. It's purpose is to help prevent the metal bolts & nuts from pulling through the relatively soft plastic spoiler if and when the driver bumps a parking curb or scrapes the front end on an angled driveway. What's more, the retainer is formed in a U-shaped channel and does not even fit properly if it is incorrectly installed on the top of the plastic spoiler. It serves no purpose on the top.

That's what I thought.

My center retainer came from the dealer with it installed on top of the plastic, and to me it never really looked right. I think I later saw a picture of a car without it on top and I experimented with mine on the bottom and it just looks and fits perfectly, like it was meant to be there. And as you say, I think it also serves a far greater purpose on the bottom.

[Peter M.]

Re: 96 Outer Air Dam Screws

Here are several photos of the air deflector (front spoiler) retainers properly installed. This installation is consistent with all model year factory service manual diagrams & installation specification sheets.

FWIW

[Pat M.]

Re: 96 Outer Air Dam Screws

Here are several photos of the air deflector (front spoiler) retainers properly installed. This installation is consistent with all model year factory service manual diagrams & installation specification sheets.

FWIW

Yup. Mine's slightly different due to the model year. And the retainer is riveted to a plastic extension that the back of the center dam lays slightly over.

When I got the car from the dealer with the retainer installed on top of the plastic dam it forced the dam down to the point where I had to shim the center brace for it to fit. When I tried the retainer on the bottom the dam was brought upward allowing the brace to fit without shims. And it just looks so much more correct to me.

[Peter M.]

Re: 96 Outer Air Dam Screws

Yup. Mine's slightly different due to the model year. And the retainer is riveted to a plastic extension that the back of the center dam lays slightly over.

When I got the car from the dealer with the retainer installed on top of the plastic dam it forced the dam down to the point where I had to shim the center brace for it to fit. When I tried the retainer on the bottom the dam was brought upward allowing the brace to fit without shims. And it just looks so much more correct to me.

Yes, now that's the proper installation.

[George C.]

Re: 96 Outer Air Dam Screws

MY & Charlie's (AKA Pat) Corvette was factory Correct and if you look at General Instuctions notes (GM part # 10149266 sheets 1 & 2) you will see the Center Metal retainer ON TOP. With the 10MM Bolts on TOP of Silver Metal Retainer head up pointing Down going through. The date of the Instruction sheet is 15MR92. I Lived these Corvette back then and all 91-96 Corvettes Had the Center Brace. (I thougt, untill looking at Peters under spoiler pic's, missing the hole where the center deflector brace goes) GM part # 10149267 (discontinued two years ago). I don't care about the 84-90 installions, (see pic of back in day looking at the first C4 convertibles) I had one of those Corvettes too and the install was different. We're talking C4's 91-96.

Peter send me your address and I will gladly send you the instruction sheets.

[Pat M.]

Re: 96 Outer Air Dam Screws

Guys check this out from the 96 service manual, to me this clinches it, at least for 96s. Look at the closeup of the brace, it clearly shows the white colored "air deflector - center" over the black "radiator lower baffle" (which I earlier called a plastic extension).

And since the retainer is riveted to the bottom of the black lower baffle, it must be below the center dam. You can even just make out the flanges of the retainer below the lower baffle with the nut between them.

George, can you highlight from your instruction sheets where it clearly shows/says differently? What you've shown to me does not show which goes on top. And why did my center dam fit so poorly with the retainer on top?

[Pat M.]

Re: 96 Outer Air Dam Screws

George when looking at your highlighted area it actually does confirm the retainer goes below the plastic dam.

Look at how the bolt goes through the plastic dam FIRST and THEN goes through the center retainer that you can just make out on the car (between the outer dam retainers). You're not seeing the retainer on top of the dam in the expoded view, that's merely the plastic outline on the dam. The retainer is on the car (on my 96 it's riveted to the baffle). So if the bolt goes through the plastic dam first, then the retainer must be below it. Right?

[George C.]

Re: 96 Outer Air Dam Screws

Looking at Pat's pic's I am going to side with Terry with possible design changes for 96. The give away is the little rubber tits where the silver metal retainer fits perfectly. My spoiler DOES NOT have a channel for the silver metal retainer to fit perfectly or those little tits sticking out. Save the Wave.>George

[George C.]

Re: 96 Outer Air Dam Screws

George when looking at your highlighted area it actually does confirm the retainer goes below the plastic dam.

Look at how the bolt goes through the plastic dam FIRST and THEN goes through the center retainer that you can just make out on the car (between the outer dam retainers). You're not seeing the retainer on top of the dam in the expoded view, that's merely the plastic outline on the dam. The retainer is on the car (on my 96 it's riveted to the baffle). So if the bolt goes through the plastic dam first, then the retainer must be below it. Right?

Pat, Take a good look at my sheet. I will send you the sheet if you like. Bolt does not go through plastic first on 95's. I will agree 96's are different.

[George C.]

Re: 96 Outer Air Dam Screws

Peter's pic's are a 84-90 Corvette. NOT a later model bumper like the 91-96 C4's. Fooled me for a minute and really threw me off.

[Pat M.]

Re: 96 Outer Air Dam Screws

Looking at Pat's pic's I am going to side with Terry with possible design changes for 96. The give away is the little rubber tits where the silver metal retainer fits perfectly. My spoiler DOES NOT have a channel for the silver metal retainer to fit perfectly or those little tits sticking out. Save the Wave.>George

Pat, Take a good look at my sheet. I will send you the sheet if you like. Bolt does not go through plastic first on 95's. I will agree 96's are different.

George I'm not trying to pick on you but it sure looks to me like the center bolt goes through the center dam (#3) first on your sheet. I see no center retainer between that bolt and the dam.

Doesn't your sheet also show the same brace close-up I posted earlier with the same configuration of the dam on top? It's not as clearly color-coded, but it looks the same to me.

And my 96 has the center brace hole and brace. But what does that have to do with the center dam retainer? The retainer doesn't interact with the brace, even when the retainer is installed above the dam, does it?

[George C.]

Re: 96 Outer Air Dam Screws

George I'm not trying to pick on you but it sure looks to me like the center bolt goes through the center dam (#3) first on your sheet. I see no center retainer between that bolt and the dam.

Doesn't your sheet also show the same brace close-up I posted earlier with the same configuration of the dam on top? It's not as clearly color-coded, but it looks the same to me.

And my 96 has the center brace hole and brace. But what does that have to do with the center dam retainer? The retainer doesn't interact with the brace, even when the retainer is installed above the dam, does it?

Pat, Take a good look, the check line shows the 10MM bolt going ON TOP of silver retainer. Send me your address and I will send you the sheet and you will clearly show the check, See pic I will post with it circled.Click on twice for larger view.Save the Wave.>George

[Pat M.]

Re: 96 Outer Air Dam Screws

Pat, Take a good look, the check line shows the 10MM bolt going ON TOP of silver retainer. Send me your address and I will send you the sheet and you will clearly show the check, See pic I will post with it circled.Click on twice for larger view.Save the Wave.>George

I can see it clearly but I just don't see what you see.

There is a line going down from the end of that bolt that FIRST goes through a hole in the center dam, #3. There is no retainer between the two. If you think the retainer is shown sitting on top of the dam in that view I disagree. As I said before, I believe that is simply a plastic rectangular outline on the dam itself, which is, in fact, the outer outline of the channel for the retainer to fit below.

For example my 96 manual shows nearly the exact same illustration, with that rectangular outline on the center dam. Yet it cannot be the retainer, because, as I said earlier, it's riveted to the bottom of the radiator baffle. So if my similar illustration does not show the retainer sitting on the dam I don't believe yours does either.

Do 91-95s have the center retainer riveted below the radiator baffle? If they do, then again, it cannot be shown to be sitting on the dam, and so the bolt goes through the dam first, then the baffle with the retainer below it.

Also, as I said, what of the brace closeup in your instructions, don't they show the baffle below the dam, with the retainer flanges below it, just as my picture does? You can even see the the little channel "hump" in profile on your instructions.

I also think your photo of your extra center dam does show a channel for the retainer below, just like mine, it's that "offset" toward the back of the dam.

I find all of this to be very persuasive that 96s, and other late C4s, had the center retainer below the center dam. But what do I know? I do appreciate your input and enjoy a good debate. Can you tell?

[George C.]

Re: 96 Outer Air Dam Screws

Pat, I think you may be right, looking at the lower radiator housing pic 6. Damn. But my spoiler didn't have the little tits like your. Gotta love the NCRS ! Save the Wave.>George

[Pat M.]

Re: 96 Outer Air Dam Screws

Thanks George, I'm far from an expert, but the evidence sure seems to indicate to me that at a minimum 96s and 95s should have the retainer below the center dam.

Look at the attached pic from Charlie's 95. Look how his center retainer appears to be riveted below his lower radiator baffle, just like my 96. See apparent rivet protruding like a little button under the retainer, between far right bolt and bolt to left.

If Charlie's retainer is attached to his baffle like mine, the 95 illustration must also show the bolt going through the center plastic dam first, so the baffle and retainer must be below it. JMHO

And I agree about the NCRS -only someone as OCD as me would even care about this stuff!