C4 front spoiler U nuts rusted

[Bob B.]

For us C-4 owners replacing or repairing the front spoiler lip. This is a petty piece of information BUT
if your U nuts are rusted and break, like all mine did the proper U Nut is available on Amazon
6mm regular extruded U nuts 58458-A ITEM 58459 BOX OF 20 is $10 or so.
I spent hours in hardware stores and buying the wrong size on amazon, trial and error.
Hopefully this petty piece of info will help somebody else- None of the repro companies seem to sell this.
I can't be the only one that has had them rust and break.
Bob

[Joe L.]

Re: C4 front spoiler U nuts rusted

For us C-4 owners replacing or repairing the front spoiler lip. This is a petty piece of information BUT
if your U nuts are rusted and break, like all mine did the proper U Nut is available on Amazon
6mm regular extruded U nuts 58458-A ITEM 58459 BOX OF 20 is $10 or so.
I spent hours in hardware stores and buying the wrong size on amazon, trial and error.
Hopefully this petty piece of info will help somebody else- None of the repro companies seem to sell this.
I can't be the only one that has had them rust and break.
Bob

Bob------

What year and what application? I cannot find that u-nuts were used for the front spoiler attachment on at least 1991-96. It seems natural that they would be used but I can't confirm their use.

[Bob B.]

Re: C4 front spoiler U nuts rusted

Joe- I am working on my 94 Convertible, red on red 7,000 mile- taking to Summerville in Oct, hopefully
It had a fair amount of light rust on the roughly 12" x 3/4" pieces that the front lower spoiler mounts with. The #6 bolt (screw) that holds the spoiler on had the U nuts attaching, roughly 8 or 10 U nuts were lightly rusted and every single one of them broke as I removed the spoiler assy.
I will get a 94 assembly manual. BTW, I have had a fair number of decals and glove box stuff duplicated, pretty high quality. I have paid the big bucks to get originals and copied them pretty well. Available to NCRS members only, just as soon not sell to the street.
I got some stuff from members for my 95 ZR-1 #3 when I was doing it, so time to return the favor.

[Joe L.]

Re: C4 front spoiler U nuts rusted

Joe- I am working on my 94 Convertible, red on red 7,000 mile- taking to Summerville in Oct, hopefully
It had a fair amount of light rust on the roughly 12" x 3/4" pieces that the front lower spoiler mounts with. The #6 bolt (screw) that holds the spoiler on had the U nuts attaching, roughly 8 or 10 U nuts were lightly rusted and every single one of them broke as I removed the spoiler assy.
I will get a 94 assembly manual. BTW, I have had a fair number of decals and glove box stuff duplicated, pretty high quality. I have paid the big bucks to get originals and copied them pretty well. Available to NCRS members only, just as soon not sell to the street.
I got some stuff from members for my 95 ZR-1 #3 when I was doing it, so time to return the favor.

Bob------

Where did you get a 1994 assembly manual? I did not think they were available for any C4 era Corvette.

Attached is a diagram from a P&A catalog. I believe the nuts you are referring to are the ones shown as #24 in the diagram as they are the only u-nuts in the entire spoiler attachment system. However, these are M8 X 1.25 thread size. They were originally GM #12337966 which was discontinued in June, 1995 and replaced by GM #11515150. The latter remains available from GM for a current GM list price of $3.32/each.


DSCN4306.jpg

[Bob B.]

Re: C4 front spoiler U nuts rusted

Joe, Interesting the diagram shows #31 to be a regular nut, my car has a #6mm U nut that slides on the lower part of the body and attaches the spoiler as a fastener and to maintain the position of the spoiler. All appears original, the spoilers have the correct part numbers and no damage other than the standard scratched the black rubber gets day one.
And I misunderstood you, I do not have a assembly manual for the 94, guess it doesn't exist.

[Joe L.]

Re: C4 front spoiler U nuts rusted

Joe, Interesting the diagram shows #31 to be a regular nut, my car has a #6mm U nut that slides on the lower part of the body and attaches the spoiler as a fastener and to maintain the position of the spoiler. All appears original, the spoilers have the correct part numbers and no damage other than the standard scratched the black rubber gets day one.
And I misunderstood you, I do not have a assembly manual for the 94, guess it doesn't exist.

Bob------


My 1992 has the #30 and #31 installed in the opposite orientation (i.e. bolt above and nut below). I'm the original owner and these parts have never been off the car.

[Terry M.]

Re: C4 front spoiler U nuts rusted

Do not take the configuration of fastners or clamps shown in the AIMs as gospel. The configuration shown does indicate a fastener is there. If a hex head or nut is shown, that may or may not be the case. If the fastener is shown installed with the head to the front of the car - that may or may the direction on the car.

Two factors affect this:
1) The line workers will install the fastener in the direction that is easiest for then. Further compilating the issue is that one worker may do it one way and the next shift do it differently. and they did not have the AIM at their workstation. The AIMs were kept in the QC office and mostly used for training and inspection purposesn

2) The images of such common items as fasteners are cut from stock printed images and pasted to the AIM page. If the image differed im configuration it was no big deal. What mattered was the part number. If the part number changed during the model year the AIM may or may not get redrawn, depending on the reason for the part number change; but the page would have the new part number on a revised page.