Topic: 67 (& 68?)Pop-open Style Fuel Cap Hardware Clarification

[67gtasanjose]

Osborn's 67 Chassis manual, page 42, top and center lists hardware for "View Z FOR G.T." (also see VIEW Z & V, at lower rh corner of page).

"FOR G.T." (aka: "FOR POP OPEN CAP") shows a need of 4 screws number 52064-S8 but does not give specs for the nut.
A bit of discovery about this nut...

It appears it is the same nut used on the STANDARD Gas Cap, that nut is 380331-S8

I have pictures of the nut I removed from my example as well as a Service Replacement-provided nut that came with a NOS C8 gas cap.

I also discovered that the screws off my fuel cap when I disassembled my car were CHROMED, not dark zinc (52064-S8)

Anybody else have info on this hardware outside the spreadsheets and Assembly Manuals?

I have been asked by a fellow member privately about these. He has found the 380331-S8 locking nut in an MPC that says it was used 65 through 70.

Richard

[J_Speegle]

My observations over the years matches what you have described as the original version. The service nut is very different from the ones I've taken off of original cars.

Sorry don't have any clear pictures in my collection that I could find - tight spaces and not a clear shot from the top/face of the nut when installed on a car. Even the couple of examples (yes when through all the pictures to be sure) didn't show enough detail to post

[67gtasanjose]

My observations over the years matches what you have described as the original version. The service nut is very different from the ones I've taken off of original cars.

Sorry don't have any clear pictures in my collection that I could find - tight spaces and not a clear shot from the top/face of the nut when installed on a car. Even the couple of examples (yes when through all the pictures to be sure) didn't show enough detail to post

Thanks Jeff. I plan to use what I removed from my example. The chromed finish screws seemed odd too, though they are otherwise "as described" in Jim's spreadsheets.
Jim and I have chatted a bit about the chromed finish not being correct. I will be putting back what I took out but others may find theirs are all S8 finish, I am OK with that.

BTW, I added to the first post, some clean images of the gas cap mounting nut I removed, images without all of my scribbling.

[67gta289]

Richard, I have an NOS service part that looks exactly like yours.  The used one I have does not appear to have any locking function.  The four mounting screws don't appear to have been chrome plated.

[J_Speegle]

Think the four depressions in the  nut may work or deform the threads enough to have originally created some deformity and in turn a locking affect. Once removed allot of that would go away =. Just a possibility


Thought I could at least post a couple of pictures since I took the time to search.  Might help a little


7R1721xx




7R1977xx

[Bossbill]

I cleaned mine a few months back and they, too, cleaned up really shiny -- just like chrome.

[67gtasanjose]

My friend from "Down Under" has provided a page from the MPC he has been viewing to determine that the 380331-S8 locking nut is used across multiple years and types of fuel caps.

I noticed also a reference to "CHROME RETAINER" (not "chrome retainerS") but they are noted as being shown to be used with the 69 & 70 service parts.

I cleaned mine a few months back and they, too, cleaned up really shiny -- just like chrome.

Besides Bill's findings on his example, it is always a possibility that Service Replacements could be a source of the "CHROMED retainer"S.

[196667Bob]

Richard : Just FYI, both the 1967 Only, and the 1960-68 MPC's (both closer to the actual time period than the 1965-72 MPC (printed in 1975), show the same 380331--S7/8 lock nut.

However, in looking at the 1966, 1969 and 1975 Ford Standard and Utility Parts Catalogs, that part is actually the "indented type" (aka "Center-Lok") type as shown in John's picture of his used one, not the "Flex-Lok" type which came on both yours and his NOS Service Parts.

I have yet to find a listing in the MPC's for the 4 retainer screws. Interestingly, the 52064-S is only listed in AMK's book, not in any of the Standard and Utility Parts Books.

Bob

[67gtasanjose]

Richard : Just FYI, both the 1967 Only, and the 1960-68 MPC's (both closer to the actual time period than the 1965-72 MPC (printed in 1975), show the same 38033--S7/8 lock nut.

However, in looking at the 1966, 1969 and 1975 Ford Standard and Utility Parts Catalogs, that part is actually the "indented type" (aka "Center-Lok") type as shown in John's picture of his used one, not the "Flex-Lok" type which came on both yours and his NOS Service Parts.

I have yet to find a listing in the MPC's for the 4 retainer screws. Interestingly, the 52064-S is only listed in AMK's book, not in any of the Standard and Utility Parts Books.

Bob

Thanks Bob.
I thought I would point out that I DO HAVE the correct nut pictured above in my first post. I have it held in my fingers. Yes. There is ALSO one of the Service Replacement type pictured that is attached to the fuel cap with a flat washer and a flat rubber washer.

[196667Bob]

I think that it is interesting that Ford went to the Flex-Lok nut on the Service Parts, since the Center-Lok ones were still available until at least 1975. My guess is because the Center-Lok nuts are "one and done" (not reusable), while the Flex-Loks can be re-used.

Bob

[67gtasanjose]

Another thread (in another year Mustang index) discussing the same retaining nut.
It would appear that the same nut is most likely used on ALL vintage Mustang gas caps, whether or not it is the pop-open type or the standard "cable secured" type.

https://www.concoursmustang.com/forum/index.php?topic=25047.0

[jwc66k]

From what I see in the Mustang Chassis Assembly Manuals (64- 65, 67, 68, 69 and 70), it's one nut per installation, non-pop open gas caps. The other four retainers are screws. In 1970, the finish changed to phosphate and oil. On the several I've had (from salvaged cars), most had a red sealer. I kept one red realer as a sample. I assume the sealer applied to all years.
I can't answer for service or aftermarket replacements.
Jim

[CharlesTurner]

So are we saying the spin nut with red sealer should be used on cars with pop open gas cap?  Would like to see a few more examples if that's the case, across assembly plants.

[67gtasanjose]

So are we saying the spin nut with red sealer should be used on cars with pop open gas cap?  Would like to see a few more examples if that's the case, across assembly plants.

It is at least a good rumor, we should look at multiple examples from all plants & year models before assuming it as actual FACT. Evidence does seem strong so far (with at least 4 examples).

[jwc66k]

So are we saying the spin nut with red sealer should be used on cars with pop open gas cap? 

I said -

- non-pop open gas caps.

What are you reading?
Jim