Self-locking nuts C8667/2 and C8737/2 (Nyloc)

[Jaguar12]

Hi,

It is about 10 years ago when I took apart my 1966 OTS, which already then not been on the road for probably 40 years. In those days I did not know about Jaguar self-locking nuts with short or long skirt (and about a lot of other E-Type things). Now the “refitting-is-the-same-as-the-removal” process has finally started and despite many hours spent on this great forum, I still have some questions. Today regarding locking nuts.

Factory Fit clearly shows the difference between C8667/2(long) and C8737/2 (short).

I have found 5 different types of 5/16x24 nuts:

Left in the picture: 11.1mm overall with 9.5mm skirt and 9.5mm overall and 6.9mm skirt, both with 2 indents (hope this is the right word) to hold the nylon.

Middle of picture: 10.7mm/8.5mm and 9.9mm/6.3mm with 6 indents.

Right: As supplied today.

The Part Catalogue specifies 8667/2 for the side frames to picture frame and to dash. On my car though I found the longer version of the middle pair in the picture with overall 10.7mm and skirt 8.5mm with 6 indents.

And now finally my question:
Should it really be the nut with the very long skirt (overall length 11.1mm or 7/16”, skirt ) or does the 4.2 have a different 8667/2 which is 10.7mm overall with skirt 8.5mm as I found them on my car and it seems to be the same as on the 26kmiles primrose yellow S1 4.2 in Factory Fit?




As for the C8737/2 short skirt, I am not sure which one is right. On the studs for the brake pedal box I found the 9.9mm with 6.2mm skirt and 6 indents (together with the „real“ long skirt one for the clutch and brake cylinders.



Long post but I hope someone has the answer.

Thanks and Greetings from Switzerland.
Daniel

[Gfhug]

Daniel, I presume you’ve searched on here for both C8737/2 and C8667/2 not just in factory fit section.
I found a few useful references to both. Including people sourcing full sets of nuts and bolts from Chuck at Monocoque.
To me the use of nyloc can be looked at in two ways. On the throttle pedal box we are not looking at structural loads, so the important thing is to make sure the nut is of a size that lets two threads to show clear beyond the nut. By having a couple of threads showing you are certain the nut is fully on.

In structural loads it can be more important to consider the height of the nut but you could always drop Chuck an email to ask what his opinion is. He’s taken apart and put together quite a few E Types and should know what to suggest.

Good luck

Geoff

[rfs1957]

The front-frame stuff supplied (to me) by Chuck is wrong, has bolt lengths that lack the nuances of the originals, and are the wrong colour, has washers of the wrong diameter, and I wouldn’t trust the nuts to be accurate to the degree that you are hoping to emulate.

[Philippe-J.]

Daniel,

you can ask Maikel Lemke, who shows himself somewhat obsessed with this issue in his videos
Here is a photo the my frame nuts on my feb. 67 OTS, which I believe are original. Hope this helps.

Philippe

[Gfhug]

Another source of hardware for the engine frame could be Andy Rayner at Hutsons . https://www.hutsonmoco.co.uk/
I had no idea of Rory’s concern about Chuck’s hardware but stand corrected, thanks.
Rory has previously listed a very good diagram of the engine frame hardware as an excellent reference for us all.

Geoff

[Series1 Stu]

I have found 5 different types of 5/16x24 nuts:

Left in the picture: 11.1mm overall with 9.5mm skirt and 9.5mm overall and 6.9mm skirt, both with 2 indents (hope this is the right word) to hold the nylon.

Middle of picture: 10.7mm/8.5mm and 9.9mm/6.3mm with 6 indents.

Right: As supplied today.

The 2 on the left (certainly the left most one) appear to be Metal Lock nuts, hence the taller collar/different format.

Regards

[angelw]

Rory Wrote:

The front-frame stuff supplied (to me) by Chuck is wrong, has bolt lengths that lack the nuances of the originals,

Hello Rory,
Are you referring mainly to the length of Thread to the overall length of the bolt? Today's bolt standards calls for, up to a certain length, circa 1.25", the whole of the bolt's shank is threaded, then, as the bolt length increases, the thread length remains the same, with the length increase being made with plain shank.

As many bolts used with the assembly of an E Type have a rather short thread length to bolt length ratio, it's difficult to get Off The Shelf bolts that match the original, and therefore, most, if not all the After Market parts suppliers are just supplying what's incorrectly available Off The Shelf. Washers and Nuts are also difficult to obtain that match the original, and again, the After Market sellers, Chuck included, are flogging what's available Off The Shelf.

In most cases, you can find bolts that have the correct plain shank length as the original, but with a Thread Length that is profoundly excessive. When required, I set up and machine batches of bolts that have the correct Plain Shank length to the correct overall length, and while I'm at it, I machine the shallow dish in the face of the bolt's head, as shown in the picture below. They don't have the correct, original markings on the face as the originals, but at a glance, they pass as original; certainly better than Off The Shelf.

The following picture is of Door Hinge Bolts. These weren't made from existing bolts, but from scratch out of bar stock. Note the Dish Feature in the face of the head.



Regards,
Bill

[Jaguar12]

Hello and thanks for the contributions.

Here is what I THINK I know so far:

- The 5/16” Nyloc nuts available today all seem to be less than 9mm in height. For the way I drive my cars today, i would not have any safety concern if the product is from a reputable supplier, but It does not really look right. And the “Fahrgefühl” with the right nuts ….
- on my car, of the nyloc in places where the parts book specifies C8667/2 I only found 4 long skirt (definitely with nylon insert) on the pedal box, the rest are of the version with approx. 10.8mm height and a shorter skirt.
- together with the foto from Pilippe’s car (thanks) and other evidence, I will assume there is 2 versions: long skirt 7/16” (11.1mm) and a version (newer?j with almost the same length but with a shorter skirt.

Now I have to find enough nuts of the long version with the short skirt to cover all the 84 lockin-nuts C8667/2 I counted in the parts book (minus the 4 long skirt). I will start my search even if it might be quite some time before I will use the last ones…

Best regards
Daniel

[astonman]

You can buy them From Aston Martin, who used the same ones at the time.
part no: Z5/16X7/16NYLOC

[rfs1957]

Rory Wrote:

The front-frame stuff supplied (to me) by Chuck is wrong, has bolt lengths that lack the nuances of the originals,

Hello Rory,
Are you referring mainly to the length of Thread to the overall length of the bolt?

Hi Bill,

No - I wasn't judging the shank/thread proportions, but the overall lengths.

I stuck the whole lot for a few dollars per kilogram on GumTree here so can't root through them any more, but many of the nuances like so-many-inches and 1/8" or 3/8" or 5/8" or 7/8" - all present in the original bolt table - were simply rounded up to the nearest 1/4".

Fine if that's all you can get, but then spare me the excited riff about "exactly what the factory used".

[Gfhug]

Another way of getting exact length bolts/screws etc is to by aircraft hardware. Still done to the nearest eight of an inch and with correct plain shank vs thread. Rather expensive though. But cheaper than buying a lathe to make your own.

Geoff

[Jaguar12]

Thanks astonman,
With your part no. I found them on ebay. They sell the long skirt version (8667/2) with the 2 divots and C8732/2, also with 2 divots.
For my car I think I need the version with 6 divots as per my photos. So the search continues….
Greetings
Daniel

[angelw]

Rory Wrote:

No - I wasn't judging the shank/thread proportions, but the overall lengths.

Hello Rory,
In my opinion, the shank/thread length proportions is important, for, in many situations, the shank is a spigot for two, or more, interfacing parts. In most cases of current manufactured bolts, the shank diameter is greater than the Thread Major diameter. The Front Brake Caliper securing bolts are a good example. An off the shelf bolt of the correct length would be threaded for their whole length, whereas, the correct bolt configuration has a very short Thread to Shank ratio.

Fine if that's all you can get, but then spare me the excited riff about "exactly what the factory used".

Yes, without having laid hands on any of the hardware supplied by Chuck, I was confident that they would be incorrect, the same as all the other After Market suppliers. You would struggle even with aircraft hardware to get bolts of the same spec as the originals used on Jaguars of the day.

Without the benefit of a lathe, in my case a CNC lathe, you can achieve correct proportioned bolts with a hand held grinder with a cut off wheel, and a bench grinder to tidy and debur the end of the bolt after cutting to length.

Regards,
Bill