ARB Drop Link threads

[Mr Cerbera]

OK Team,

I'm reaching the end of my teather.

Life with BlackBeauty is breaking my soul.

The latest debacle:

A very kind PHer GAVE me an ARB Drop Link via post.
Inspired by his generosity, I ordered the second so that I could replace the pair.

I was told that the gift was missing a nut but, as I had several spare, I didn't think it would be a problem.

When the two Drop Links arrived, I interchanged the three nuts to ensure that they were matched.
When I went to the mancave, none of mine fitted.

Strange, thought I, Oh well I'll use the nuts from the current fitment ubtil I can find a replacement.

So, off come the Drop Links in place and, guess what ? not only did the current nuts not fit the new Links
but my nuts didn't fit any of the Links.
Three separate thread types for one application !

Now I know that many frightening stories exist of how varying pieces were taken
randomly from parts' trays during assembly at the factory
but
Shirley, the chances of all three threaded sources being different are astronomical !

I must be doing summat wrong and I beg you and all your kindnesses to give me a clue as to what.

The nuts are a gnat's bk over 17mm but I don't have a clue what thread they are.


Any hints you can give would be internally gratefully received.

Ta !

PJ

[O mage]

Im pretty sure the nuts are or should be 7/16 UNF thread size which will then be 11/16 spanner size. If it looks a fine thread or if not could be UNC

Edited by O mage on Sunday 28th June 21:32

[Mr Cerbera]

O mage said:

Im pretty sure the nuts are or should be 7/16 UNF thread size which will then be 11/16 spanner size. If it looks a fine thread or if not could be UNC

Edited by O mage on Sunday 28th June 21:32

Cheers O' Can you recommend a good thread guage ?

Ta !

PJ

[O mage]

I got mine with a tap and die set but if you count the threads per inch UNC is 14 threads per inch and UNF is 20 threads per inch thats at 7/16ths

[Mr Cerbera]

O, you are a STAR !.

The thread from the new drop link to go on appears to be 20 tpi....



The Nut I was trying to put on, which I think is 17mm, is 16 tpi...



The confusion comes when I look at the old Drop Link.
They both take a 16mm spanner to their heads.
but, the Bolt is a larger diameter than the Screw and appears to be 18 tpi....



The lower screw looks like 22 tpi to me



I would very much value any comments you have.

All the Best,

PJ

[Adrian@]

Try metric fine, I have a box of them on the shelf here esp for the drop link. A@

[Mr Cerbera]

Adrian@ said:

Try metric fine, I have a box of them on the shelf here esp for the drop link. A@

Cheers Aide@


_______________________________________________________
ETA
Now that you've popped your head over the parapets....

I have a 2001 Cerb - which I've owned for 15 years - never had any probs with threads before.

Now, in the last 3 months I seem to be cross-threading almost everything I touch

There is a Chassis Brace, under the chassis, which is retained by 10 x (I thought) 17 mm screws.

I have tried to replace them with Allen screws and Torx screws with varying degrees of success.

Is there a source of information for 'which threads are used' on the various areas of the car ?

Thanks for reading this (very) vague question.

Edited by Mr Cerbera on Wednesday 1st July 11:17

[pmessling]

Chassis brace is M10,

[O mage]

m10 standard and m10 fine are both used but most of the metric threads they used are standard i would say. Prop bolts they are unf 9 /16th i think.

[TwinKam]

Metric has its own 'version' of UNC & UNF.
There are 3 different pitch M10s in use...

M10 x 1.50 (coarse) most common
M10 x 1.25 (fine) less common
M10 x 1.00 (exra fine) least common (mainly Jap)

The chassis brace bolts will be coarse.
Ball joint threads incl track rod ends, drop links, brake banjos and bleed screws often have fine (or even extra fine) as coarse is considered too coarse in these applications.
A thread gauge is handy if your eyes are not accustomed to determining the differences, or measure say 10 threads with a vernier. Or keep a selection of known (labelled?) bolts and nuts for trialling.

As for M10, the same applies to M12... (1.75, 1.50, 1.25) and so on up.
I have also seen M8 x 1.0 (fine) but I don't think there's an M6 fine.
Get yourself a 'Zeus' engineers' ready-reckoner, threads are fascinating!

Edited by TwinKam on Wednesday 1st July 13:57

[TwinKam]

P.S.
Bolts are determined by their thread size, not by their spanner size, as this can vary.
So the '17mm' chassis brace bolts above are in fact M10 and may have a 17mm hex head or a 8mm internal hex head ('Allen' or 'cap' head). M10 nuts are usually 17mm but can be 15mm or 16mm hex!
And the '9/16" ' propshaft (flange) bolts above are 3/8"UNF... 9/16" being the spanner size.

Edited by TwinKam on Wednesday 1st July 13:59

[Mr Cerbera]

Thanks Guys - for all your info

BUT !!

Rik, You are a STAR

You can't imagine how difficult how all that is to explain to a Luxembourger

Think I'll have to resort to The Experts
I am forever in your Beer-Debt

[TwinKam]

I also should've said...
Whereas imperial thread pitch is described as threads per inch (tpi), metric thread pitch is simply defined by.... err... pitch ie the distance between two peaks. So when you're trying to identify a thread, it's helpful to measure both to see if one's a familiar value and the other isn't... (this is where Zeus comes in handy, listing all the pitches of all the threads).
As a very rough guide, taking 1" to be 25mm, you can see that:
25 tpi = 1.0mm pitch
and
12 1/2 tpi = 2.0mm pitch
So, returning to your pics above, and using some basic maths:
Approx 20 tpi = roughly 1.25mm pitch ....oooo that sounds like a familiar value ....if 10mm dia then it could be M10 fine.
Approx 18 tpi = roughly 1.4mm pitch ...not so helpful.
Approx 16 tpi = roughly 1.5mm pitch... aha... possibly our common old friend, M10 coarse.
Last tip; if you're finding it hard to measure the pitch on a bolt, ink the thread (eg Sharpie) and press it on a piece of paper, then measure that

Edited by TwinKam on Wednesday 1st July 22:34

[Mr Cerbera]

Thanks for the latest stuff - superbly helpful

TwinKam said:

....
Get yourself a 'Zeus' engineers' ready-reckoner, threads are fascinating!

Didn't have much luck finding "Zeus'" bits

BUT

I did find This beauty

_____________________________________________________________________________________

ETA
I am such a dork with the Web.
I didn't realise that "Zeus" is a book.
Now ordered

Ta !

Edited by Mr Cerbera on Thursday 21st January 14:20

[Stunned Monkey]

M10 x 1.5 according to my record of buying rod ends for mine.

I also bought boots to keep them happy and sealed (and full of grease)

fb.com/mys6cerbera

[Mr Cerbera]

Adrian@ said:

Try metric fine, I have a box of them on the shelf here esp for the drop link. A@

Hi Adrian,

Sorry that it has taken 5 months to get back to you

BUT

I have visited every stockist in Lux now and those that recognise the existence of M10 (fine) do not stock it and say that I'll have to order it online.

Sooooo, I hope that I can still take advantage of your kind offer and order some from you.

Unfortunately your account here is not set-up to accept PMs so may I ask you to suggest a form of communication. Please PM Me if you have time.

All the Best,

Paul

[Jhonno]

Mr Cerbera said:

Adrian@ said:

Try metric fine, I have a box of them on the shelf here esp for the drop link. A@

Hi Adrian,

Sorry that it has taken 5 months to get back to you

BUT

I have visited every stockist in Lux now and those that recognise the existence of M10 (fine) do not stock it and say that I'll have to order it online.

Sooooo, I hope that I can still take advantage of your kind offer and order some from you.

Unfortunately your account here is not set-up to accept PMs so may I ask you to suggest a form of communication. Please PM Me if you have time.

All the Best,

Paul

M10 Fine Nyloc

[Byker28i]

Westfield Fasteners are usually a good supplier
https://www.westfieldfasteners.co.uk/

[Mr Cerbera]

Jhonno said:

M10 Fine Nyloc

Oh John, Gold Nuts, YOU ARE A STAR !!
Bling Bay for Christmas

Byker28i said:

Westfield Fasteners are usually a good supplier
https://www.westfieldfasteners.co.uk/

Hi Dave,

Yup, I discovered that site in the middle of last year
BUT
my mistake was in not knowing the variation in thread sizes and, unfortunately, ordering stuff which was not compatible.

Try, for example, finding some machine screw, in anything but 1.5mm (Course)

Thanks for your suggestion, though

[Mr Cerbera]

Sorry but I like to close my threads with a positive
AND THE ANSWER

TVR Parts (and Racing Green) supplied ARB Drop Links now have M10 fine threads (both top and bottom)

Thanks all