C2 vented gas cap

[Jim S.]

Re: C2 vented gas cap

I agree !

Thanks Joe!

Jim

[Stuart F.]

Re: C2 vented gas cap

I bought my #3952808 about 3 years ago from my local Chevy Dealer who ordered it out of a GM warehouse, I believe in Atlanta. I have the receipt for it in my file; $24.77. Darn, either the price went way up since then or my GM employee discount is greater than I thought. What is it from GMpartsdirect?

I get the "whoosh" too, but I trust Joe's explanation of it not being designed to correspond to ambient, so I just accepted that. My car is finicky anyway, so some times it runs strange until a shut down and restart, like what happened when I first reported it.

Stu Fox

[Joe L.]

Re: C2 vented gas cap

I bought my #3952808 about 3 years ago from my local Chevy Dealer who ordered it out of a GM warehouse, I believe in Atlanta. I have the receipt for it in my file; $24.77. Darn, either the price went way up since then or my GM employee discount is greater than I thought. What is it from GMpartsdirect?

I get the "whoosh" too, but I trust Joe's explanation of it not being designed to correspond to ambient, so I just accepted that. My car is finicky anyway, so some times it runs strange until a shut down and restart, like what happened when I first reported it.

Stu Fox

Stu------


I believe the price of the 3952708 did increase rather dramatically over the course of the last several years. Why? Well, as far as I know, Stant is and always has been the only manufacturer of this cap. Once-upon-a-time, Stant was probably manufacturing these in fairly high volume. Nowadays, that volume has probably fallen off to a trickle. So, I expect they told GMSPO that if you want us to continue manufacturing these, the per unit cost has to go up significantly. I'm glad GM acceded. Otherwise, you know what happens: the discontinued sign goes up and Stant ceases manufacture of the cap entirely.

So, what's the difference between a current 3952708 and one manufactured in 1969, the first year of its use? Only two things I know of: the zinc plating is somewhat brighter and the Stant Manufacturing logo stamped on the underside has changed configuration.

What about difference between the 3952708 and the GM #3843576 used from L63 to E68? Same as above PLUS the 3843576 used a brown cardboard gasket whereas the 3952708 used a black neoprene rubber gasket.

So, what about the later 68-only GM #3921689? I don't know.

By the way, if one wants a cap to relieve to ambient pressure, use the early 63 cap with a hole and no valve, at all OR use the GM locking cap which also uses a hole only. However, I don't recommend either.

[Jim S.]

Re: C2 vented gas cap

I bought my #3952808 about 3 years ago from my local Chevy Dealer who ordered it out of a GM warehouse, I believe in Atlanta. I have the receipt for it in my file; $24.77. Darn, either the price went way up since then or my GM employee discount is greater than I thought. What is it from GMpartsdirect?

I get the "whoosh" too, but I trust Joe's explanation of it not being designed to correspond to ambient, so I just accepted that. My car is finicky anyway, so some times it runs strange until a shut down and restart, like what happened when I first reported it.

Stu Fox

Stu
GM parts direct

3952708

Fuel Tank Filler Cap

CAP

1

$40.86

Jim

[Ed S.]

Re: C2 vented gas cap

Jim
Thanks - this appears to be the best price available for a 3952708. I checked it on on the GM parts direct website. They do not show a pic or any other description other than "fuel tank filler cap". Not having much experience with this vendor (or others for that matter), does anyone know if items offered by GM parts direct that are "genuine GM parts", like this cap for instance, are actually just that and will pass top flight scrutiny? In other words, is this cap the real deal or a reasonably good aftermarket reproduction that will function properly but also result in a top flight point deduction?

[Stuart F.]

Re: C2 vented gas cap

Ed;

I can't speak to the judging aspects for parts from GM Parts Direct, but what I have got from them were the same parts I would get from my local Chevy dealer - so far. The last thing I got from them were a couple of B-28 VAC's. I had ordered some from several different Vette parts vendors and none would meet a performance test with my Mityvac. They were marked correctly and looked pretty (may have passed judging), but I had to send them back. The ones I got from GM Parts Direct were spot on (not sure you can even get them anymore).

Joe is right on about the latest #3952708 cap. The one I got is real shiny (pretty). And, if I feel real concerned about the "Whoosh", i will put either my original cap with the single hole (not quite as pretty) or my locking cap back on. My purpose for getting the dual valve 708 cap was to try and reduce the gas smell in my attached garage. I thought too that my original might be more valuable to the "Gas Cap thieves" at car shows. The locking cap looks nice (being chrome), and will slow the thieves down that don't have a nickel, but I didn't like having to clean off the discoloration from he gas fumes all the time.

Stu Fox

[Jim S.]

Re: C2 vented gas cap

Jim
Thanks - this appears to be the best price available for a 3952708. I checked it on on the GM parts direct website. They do not show a pic or any other description other than "fuel tank filler cap". Not having much experience with this vendor (or others for that matter), does anyone know if items offered by GM parts direct that are "genuine GM parts", like this cap for instance, are actually just that and will pass top flight scrutiny? In other words, is this cap the real deal or a reasonably good aftermarket reproduction that will function properly but also result in a top flight point deduction?

Ed,

As far as I know G.M.P.D. only sells GM parts, and like Stu said, the same ones you would get from your local dealership .

As to NCRS scrutiny, that is another story. Often even a few years later , the "real" GM part is not the same as the ones used on the assembly line . GM is concerned with function and fit , not looks . Even Genuine GM Reproduction Parts are often distinguishable from originals in one way or another to judges.

This cap may be right on ,or not , I don't know. However if NCRS judging is your main criteria, you should always strive to find a clean or repairable original part.

Jim

[Joe L.]

Re: C2 vented gas cap

Jim
Thanks - this appears to be the best price available for a 3952708. I checked it on on the GM parts direct website. They do not show a pic or any other description other than "fuel tank filler cap". Not having much experience with this vendor (or others for that matter), does anyone know if items offered by GM parts direct that are "genuine GM parts", like this cap for instance, are actually just that and will pass top flight scrutiny? In other words, is this cap the real deal or a reasonably good aftermarket reproduction that will function properly but also result in a top flight point deduction?

Ed------


The cap that GM Parts Direct sells under GM #3952708 is a genuine GM cap. In fact, it would be illegal (and probably a violation of their franchise agreement with GM) for them to sell any gas cap under part number 3952708 if that cap was not a genuine GM part. After a part is GM-discontinued but picked up by the GM Restoration Parts Program, a dealer can sell it under that number, though. Of course, the latter situation has not occurred yet with respect to the 3952708 cap. Keep in mind, though, that while the 3952708 is a genuine GM part, like many other parts, it is NOT manufactured by GM. It and its predecessor caps are and were always manufactured by Stant.

The current GM #3952708 caps differs from original 3952708 caps used in PRODUCTION and once available in SERVICE by the two differences I described above. Those differences may result in a judging penalty.

[John M.]

Re: C2 vented gas cap

Ed, If you're looking for a no deduct cap contact Joe Perri, he does a first class rebuild and may have some that he could sell without your core.
corvetteillinois@comcast.net

Definitely worth a try.
John

[Gene M.]

Re: C2 vented gas cap

Not to drag on on this topic but to share some info for those interested in the judging of said gas cap. The current flight judging forbids removal of gas caps (or anything) from the car for judging. So the gasket and logo will not be looked at. But I will share that the current available gas caps have two spot welds securing the handle that are of lesser size than originals that judges will key in on. So now the owners as well know the same information.

[Jim S.]

Re: C2 vented gas cap

"current available gas caps have two spot welds securing the handle that are of lesser size"

Gene,

I thought it was the other way around . No ? Or was that a while ago, and now they have over compensated to the opposite ?

From a previous post :
I found a photo on my hard drive. The original is on the left.

Attached Thumbnails

[Gene M.]

Re: C2 vented gas cap

Jim,
The one on the right is bigger than any I've seen. Must be over compensated now.......

The left is what I would like to see.

[Jim S.]

Re: C2 vented gas cap

Stu------


I believe the price of the 3952708 did increase rather dramatically over the course of the last several years. Why? Well, as far as I know, Stant is and always has been the only manufacturer of this cap. Once-upon-a-time, Stant was probably manufacturing these in fairly high volume. Nowadays, that volume has probably fallen off to a trickle. So, I expect they told GMSPO that if you want us to continue manufacturing these, the per unit cost has to go up significantly. I'm glad GM acceded. Otherwise, you know what happens: the discontinued sign goes up and Stant ceases manufacture of the cap entirely.

So, what's the difference between a current 3952708 and one manufactured in 1969, the first year of its use? Only two things I know of: the zinc plating is somewhat brighter and the Stant Manufacturing logo stamped on the underside has changed configuration.

What about difference between the 3952708 and the GM #3843576 used from L63 to E68? Same as above PLUS the 3843576 used a brown cardboard gasket whereas the 3952708 used a black neoprene rubber gasket.

So, what about the later 68-only GM #3921689? I don't know.

By the way, if one wants a cap to relieve to ambient pressure, use the early 63 cap with a hole and no valve, at all OR use the GM locking cap which also uses a hole only. However, I don't recommend either.

FYI . The Latest Message from GM Parts Direct : Part Number 3952708: Cancelled (PART HAS BEEN DISCONTINUED FROM GM)

JIm

[Donald H.]

Re: C2 vented gas cap

I may be wrong, its happened before, but I suspect that the cap sold by GM #3952708 is the same cap sold by Paragon and others. The cap I purchased (and picture below) has the Stant logo on the back side. So I assume it is manufactured by Stant and seems to me that Stant likely isn't producing two different caps, one specifically for GM and one for the other suppliers. If that is the case, seems silly to pay $70+ to GM when you can get the same cap for $30 elsewhere. Unless you just want it to come in a GM box. Of course as I said, I may be wrong in my assumptions.

In the pictures attached, the cap on the left is a Joe Perri restored original and the one on the right is the Stant cap I got from Paragon. You can see the difference in the spot welds. On the inside of the cap, the most telling difference I have found is that the outermost circle in the SM logo has almost disappeared in the current production of caps. I assume this is due to wear on the stamping dies. The pictures aren't great, but if you look closely at the new cap (right in the pictures), there is only a small section of the outermost circle still there while on the original, the outermost circle is complete.

Don

[Joe L.]

Re: C2 vented gas cap

FYI . The Latest Message from GM Parts Direct : Part Number 3952708: Cancelled (PART HAS BEEN DISCONTINUED FROM GM)

JIm

Jim------


Yes, that discontinuation occurred very recently, I believe with the December GMSPO update. It had to happen eventually. The last car that used this cap was built 45 years ago. There could be two reasons why GM discontinued the cap. First, it could be there sales volume dropped so low (especially enhanced by the $77 GM list price), that they dropped it for that reason. More ominous, though, is the possibility that Stant has ceased manufacture of the cap. That means all sources dry up.