thread types

[mikeydude]

Does anyone know what the thread type is on the front suspension ball joints and track rod ends? I wanted to replace them with new nylocs but they must be a fine thread not standard ISO M types.

[dapinky]

I know they are a finer thread than standard - 'cos I'm just having a breather from stripping my front suspension parts in the garage!

I'm building up a complete assembly to replace it all in one hit, and I've got the nuts here somewhere in a big box of Stainless fittings!!!

Give me a mo and I'll go and measure the thread on the ball joint for you.....

[dapinky]

Ball joints are M12 x 1.5 thread (M12 metric fine) - I havent got a track rod end here, but would expect it to be the same.

The bottom ball joint uses a thinner nylock nut (to avoid touching the rubber boot on the driveshaft, and more importantly, to allow removal) - a standard one will go on, but if/when you come to remove it, there isn't quite enough room to undo it fully from the thread without it 'grounding out' on the hub (although you can split the ball joint after undoing it most of the way, allowing it to drop a bit, so the nut can be undone fully).

A normal height nut can be ground down a bit if you need to do so (thats why I'm using stainless ones!).

Easily availlable from my local nut & bolt shop, and quite a few listings on ebay.

[mikeydude]

I know they are a finer thread than standard - 'cos I'm just having a breather from stripping my front suspension parts in the garage!

I'm building up a complete assembly to replace it all in one hit, and I've got the nuts here somewhere in a big box of Stainless fittings!!!

Give me a mo and I'll go and measure the thread on the ball joint for you.....

That would be great! ...Is it OK to replace these with stainless as I am told that they are not high tensile so not strong enough for suspension applications etc.

[mikeydude]

Wow....quick reply...you have told me everything I need to know!...I think my bottom ball joints have had the nut replaced in the past for a normal full height version as I had to loosen then split the joint to make enough space to remove the nut, I have had them on and off a few times over the years so I have been putting threadlock on them..I think it's time to replace them now....I did notice that one side had a thick washer on and the other did not!...It's not clear in the manual as to if it's supposed to have one, I assume it should...if anything it exposes more of the nut so that it is easier to get a spanner on it (wrench I believe for US readers!).

Still a bit concerned about the stainless..I have heard that high tensile stainless are available but I have never seen any.

I am taking off the gearbox now as I need to replace badly leaking drive shaft seals ...plus the numpty that replaced my clutch for me over tightened the tittle bolt that hold the tab for the speedo cable in place in the gearbox...I came to check the gearbox oil and snapped it off trying to get it undone.....I was not very happy with him to say the least.

[dapinky]

Mike,

2 things for you here.....

...it is possible to change the driveshaft seals with the gearbox in situ (not so easy, but possible - I used a piece of 2 x 2 timber to drift mine in!)

...secondly, stainless comes in many types (as do lots of other materials!).

A1 - A5 are the classifications, and then sub-divided by tensile-ness (doesn't sound like a proper word, but you know what i mean!).

'Standard' stainless bolts are probably A2-70 (with 70 being the tensile strength), which is insufficient for most suspension bolts (only my opinion, but as it's lower than an 8.8 BZP HT bolt, it doesn't seem like a bad guess).

The A2 classification means it wont rust in normal environment, but will in strong salt (marine) applications.

Then you go up to A4 - which are corrosion resistant in a marine environment.....

'Standard' A4 bolts are also given a rating of '70', but have a higher strength than As-70 (due to the chemical composition of the alloy)....

..then they do an A4-80 (which I have bought), which has the equivalent sheer strength as an 8.8 carbon steel bolt....


There are some bolts in the suspension which require an even higher strength (12.9) - notably the ones through the top wishbone and those holding the shock absorber to the cast-iron lumps which attach to the Track Control Arm (lower wishbone) - they are the only ones I haven't sourced a stainless replacement for, as to get stainless in that grade is ridiculously expensive.

So far, I've had a few very tight (rusted solid) bolts, a few which needed the angle grinder, and one (M8 holding the end plate to the raft) which I am drilling out slowly

I suppose they have been in place for 23 years so it's to be expected, and I hope never to have to take them off again, but you never know. I'm sure I could have got away with re-using most of the old bolts, and a bag of new nylocks, but project-creep has taken over!!!!!

Surprisingly, none of the big bolts actually stuck into the bushes, and were all freely-rotating - obvious testamony to the advantages of copperslip on the shaft.

One extra thing I have done is to re-cut the thread on the ends of the big long stud which goes through the top of the raft and hold the top wishbones - the threads were horrible and it took a lot of effort to get the old nylocks off (the shaft itself was good - copperslip again!) - having done that, I dipped the threaded ends into a jar of phosphoric acid to convert the remaining rust to iron phosphate, and give it some future protection.

[mikeydude]

Many thanks for the info Dave.
Could i ask where you sourced the high tensile stainless nuts from? as my local hardware place do not have them and neither does ebay by the looks of things
I have had the A2 type on the car in non critical areas for five years and there is no sign of corrosion at all.
I am sure A2 80 would be fine if they are easier and cheaper to source?

[mikeydude]

Ah...found some on ebay.... ah ...wrong thread....

[dapinky]

For most of my nuts, I went to nutandboltshop.com/, but for the A4-80 bolts i had to get some from www.westfieldfasteners.co.uk/, but they didn't have the fine thread nylocks, so I had to get them from ebay - "only" A2 grade, but i reasoned that they are not in a position where they take a huge strain, and are more to keep the ball joint in place, if they were a high strength piece, they wouldn't be in a fine thread.

[GeoffSmith]

Bumax supply aerospace/nuclear industry with 8.8 and above but I've never found a distributor.

My humble opinion is that the ball joint nuts are only holding the tapers together and it is these that take the strain. At least that's what I told myself when I found one of my Minis was missing the bottom nut and it was all held together with rust.

[Brit-Car-Nut]

They are only available in Class 10 (grade-8), Zinc Plated by my supplier. 10 nuts for $6.27.

I order hardware often, so if anyone wants me to get something...

Look at http://www.mcmaster.com for any hardware needs. They are great for nuts and bolts, not so much for other items.

[dapinky]

Bumax supply aerospace/nuclear industry with 8.8 and above but I've never found a distributor.

Yep, them's the ones which cost an arm and a leg! (and the only place I could actually buy some was in Australia, so I didn't bother!)

[Brit-Car-Nut]

http://www.seascrew.com/browse.cfm?l=0000000551

This page shows they have THIN Stainless M12 1.50 Locking nuts A4 (Reference #FPL12-1.5) for 3.89 each

[mikeydude]

Thanks for everyones help.
I think I will just replace them with normal 8.8 nuts rather than s\s ....many thanks for telling me the correct type Dave