Nuts and bolts
 

Hello all
I find myself yet again in this "NLA" situation. This time for something I thought would never be an issue. Bolts. More specifically, the greens coated rear control arm bolts.

N10346201
N10326201

Now whilst I'm fairly confident that I will be able to find something from another (newer) model, even if I have to cut something down to suit, what are the alternatives?

Do any of you have some magic solution that you use to coat standard readily available bolts?

Happy new year all by the way.

Cheers Frank

You can buy generic metric 8.8 high tensile bolts mechanically galvanised from the right bolt shops (or online).
I haven't looked for 10.9, but they're probably around too if you look hard enough.

You can also buy generic control arm fastener kits from VW/Audi, and I think Meyle sell them too:
Eg,
N10425302
N10770901KT

That was just a very quick google, so with a bit more effort, you shoikd be abke to find something...

There is a thread coating analagous to copperease but specifically for bolts used aluminium frames. Copperease, of course, PROMOTES electrolytic action between steel / alu and should not be used.
However, I have forgotten what the name is unfortunately but I remember it being recommended by MJ. I am sure that she will advise.+++

I think the nyloc nuts are NLA as well IIRC, or possibly they were just stupidly expensive compared to 10p each for stock bright plated nylocs. I use C5 A6 parts these days instead as they are close enough.

M12 fine pitch bolts tend to only be available in socket-head from hardware suppliers so OE is really the only option if you want to retain an OE look.

The grease I use for steel fasteners in contact with aluminium is an aluminium-based anti-sieze. https://www.juicelubes.co.uk/aas-juice/

The green coating on factory hardware is also designed to be compatible with aluminium.

I always thought green coating is threadlock to stop them from undoing, not antiseize.

I do like the idea of using A6 hardware. Most Audi front suspension is similar enough to get away with that. The D2 only has 1 arm that is different in the way it mounts to a C5.


The green is referring to that greeny/bluey tinge of the galvanising on genuine hardware.
It's a specialised coating for corrosion protection for alloy and steel. From what I've seen, BMW use a similar (or the same?) coating.

However as Zinc is more reactive galvanically than both Alluminium and Steel, Zinc coatings in general offer excellent protection.
However all coatings on bolts are sacrificial in nature, which means the coating gets sacrificed for protection of the base material/s.
Because of this, in exposed environments (like suspension) a Zinc plate (shiny/bright Zinc), which is only a few microns thick, won't survive long.
Galvanised coatings (hot dipped or mechanically applied) are far superior and will last a long time.
They are more than adequate for the job if you can't get genuine hardware/coatings.

I have most of the bolts I need for my rear suspension refurb bought directly from the main dealer (apart from the ones that are NLA). After inspecting them, they are all grade 10.9 and coated in (what I can only find as something called) "greenkote". I spent a couple of days searching the net and cannot find a retailer who will sell direct to the public. It seems the ones I could find are more set up to sell on an industrial scale or are companies specialising in coating something you send to them.

You can, quite easily find 10.9 zinc plated bolts and whilst these will not be as corrosion resistant as original equipment, they may be the best we can get easily.

Galvanised (HDS) bolts will give better results but I can only find them in grade 8.8

Any bolt refresh kits that I can find all seem to be for the front end of the car. I'm also not sure if these have the green coating or not.

At the moment it looks like I'll simply be buying other genuine coated bolts from Audi (other suspension bolts) but a different part number. They'll be slightly longer but it's easy enough to cut them down.

Thanks everyone for your replies