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Upper Ball Joint Threads (again)
The Doc - 10/8/07 at 09:43 AM

OK we are familiar with the problem - Not enough thread showing etc. I would be interested to know what people have done here.

No problen turning a couple of mm off a nut (as I have a lathe) but to get a couple of threads to show makes a pretty damn thin nut!

Do we need threads showing if the nut is castle nut/split pin?

Just how thin do we think this nut can be?


Rob Lane - 10/8/07 at 10:03 AM

After having a nut strip its threads and cause a wheel collapse I have now checked this over.

It would appear with a new balljoint fitted that the end of the thread/beginning of the taper is actually further up in the upright hole.

I have now carefully dressed the underside of the upright top and removed approx 2-3mm from the nut land area.
This allows more thread exposed and the nut to lock down correctly.

I have radiused the area to the back of the hole to avoid any stress point.
A precaution I believe because the original had a very sharply defined cut off.

The amount of metal in the top joint fastening is not compromised by this and certainly appears of adequate thickness to accomodate a few mm of metal removal.

I hope my description makes sense.
Rob Lane

[Edited on 10/8/07 by Rob Lane]


SyKaTurbo - 10/8/07 at 11:26 AM

I haven't got a car assembled to fully understand this thread. Any pics would be helpful!


t.j. - 10/8/07 at 11:57 AM

So with shortening the upright, problem solved?

I like the idea better than shortening the nut.

One thing is also important, let the coilover do the stop in full drop and not the transit ball-joint.

Btw: i'm using the M20x1,5 version, which has the same problems.


907 - 10/8/07 at 01:33 PM

quote:
Originally posted by SyKaTurbo
I haven't got a car assembled to fully understand this thread. Any pics would be helpful!




This is the little blighter.

I still haven't done mine. I don't fancy a thin nut and would prefer to thin the casting.
I did wonder if drilling a 2mm hole and using a split pin would be acceptable.
Sort of castle nut without the castlellations.

Paul G Rescued attachment chassis and clutch 072.jpg
Rescued attachment chassis and clutch 072.jpg


The Doc - 10/8/07 at 02:13 PM

So it's take the whole f***ing assembly apart then. I really didn't want that.

Oh well, that's life. Just a thought - has anyone cottened on to this and started knocking them out with a little more thread.

Or-do some makes have a little more thread than others, anyhow?


The Doc - 10/8/07 at 02:16 PM

By the way 907 - that's before you put your cycle wing stay under the nut! If, of course, that's the route you're going.


The Doc - 10/8/07 at 02:20 PM

Anyone reamed the hole?


SyKaTurbo - 10/8/07 at 03:32 PM

Ah right, i'll be using the Sierra upright so don't think it will apply to me.

Does look a little dodgy. Can you not use one of the nuts with the flat bottom and a deformed thread to lock it in place? Rescued attachment locknut.jpg
Rescued attachment locknut.jpg


907 - 10/8/07 at 03:46 PM

quote:
Originally posted by The Doc
By the way 907 - that's before you put your cycle wing stay under the nut! If, of course, that's the route you're going.







Absolutely, another 3mm up the chute.

Would reaming squash the rubber cup too much?


Paul G


The Doc - 10/8/07 at 04:41 PM

OK I've done a lttle research and found that the ball joints are not identical. With some the thread stops much sooner than others which have a couple of threads missing in favour of a 'shoulder'.

I think I'm going to pursue the line of acquiring the joints with the longest thread I can find, castle nut and a new hole drilled for a split pin as near the end of the thread as I dare


MikeRJ - 10/8/07 at 04:56 PM

quote:
Originally posted by 907
Would reaming squash the rubber cup too much?


You would have to be very carefull that it didn't restrict the articulation of the joint. The consequences would be far worse than a disgruntled SVA tester...

[Edited on 10/8/07 by MikeRJ]


caber - 10/8/07 at 05:03 PM

My TREs came with different thread lengths one with a castle nut the other with a Nyloc. No surprise the one with the nyloc is nearly OK the other is no way! I am inclined to grind a fresh flat for the nut to land on and drill and pin full nuts on to the TREs.

Caber


David Jenkins - 10/8/07 at 05:44 PM

Here's a copy what it says in my Westfield build manual: Rescued attachment westie-upright-mod.jpg
Rescued attachment westie-upright-mod.jpg


907 - 10/8/07 at 06:29 PM

Well, if it's good enough for the

Westfield Technical Otline


it's good enough for me.

Paul G

thanks David for finding that.


Rob Lane - 11/8/07 at 08:17 AM

That's exactly what I have done to get the thread fully exposed.

The thread failure could be down to one or two things.

The lack of threads fastening in nut.

Wrong nut fitted. i.e. less than 8.8

The second is quite possible, I have had them apart a few times whilst fabricating new wishbones and may have used a 'soft' nut.

The balljoint threads still had full thread shards left in them, suggesting stripping by wrong type of nut. (My fault)

To be sure this time, as well as thinning the upright slightly I'm going to drill and lockwire the nut !!!


The Doc - 11/8/07 at 01:46 PM

In the end I put the ball joints on the lathe - just do-able with my lathe set up and turned 1mm off the taper. A shave off the castle nuts and it's looking good.

We still have the full range of movement in the ball joint and the rubber boot is not unduly squashed.

All seems fine - Anyone else go this route?

I'll put some pics up later

Mike


The Doc - 11/8/07 at 04:39 PM

Here it is fitted


The Doc - 11/8/07 at 04:40 PM

Well it is now! Rescued attachment Castle Nut.jpg
Rescued attachment Castle Nut.jpg


The Doc - 11/8/07 at 04:41 PM

No it's not - what's the problem here?


The Doc - 11/8/07 at 04:42 PM

There it is!