Please Read - 2b Wishbones

[Guest Angel Boy]

All,

I know this has been mentioned on a number of occasions by various members, but I would like to repeat the message again because it happened to me today.

 

Was out in the car yesterday bombing along the country roads as you do. The steering felt a bit vague but I thought it was the road etc. Went to go out in the car this morning for more of the same, but checked the front to see if anything was amiss after the vague-ness of yesterday. Divers side ok, passenger side lower ball joint held on by two threads The taper was completely out No taper joints have been modified.

 

Now I have made a consious effort to make sure that all the bolts have been tight after hearing some of the stories from fellow members. For those of you who have wishbones it is definately worth checking them and not just visually either. I checked the drivers side with a spanner after the passenger side find and it was also coming loose. I might be ok now and it might just be a one off, car settling in etc but it could have all so easily gone pear shaped.

 

The car had done around 500 miles since the build.

 

Please bare this in mind next time you are pottering around in the garage.

 

Many thanks,

Andy

[Guest TerryBarry]

Hi Andy,

I'm pleased to note that you are not writing from your local A&E unit

I read this and I'm relieved that my car is still some six months away from completion (Who am I kidding)

It would appear that the taper joints are settling down.

I'm assuming that the nylocks are not backing off. Otherwise I'll stop driving anything.

There is the other reported problem with the lower wishbone joint unscrewing itself.

On my kit the upper wishbone joints are Ford replacement units as are the track rod ends.

The lower wishbone joint that goes into the swivel hub is not a Ford type - I believe that it's possibly Rover or Pegueot.

Does anyone out there have the facilities to measure the taper (length and angle) of the supplied components compared to the taper in the Sierra swivel hub.

On the lower wishbone I'm either going to insert a split pin or make up a screw locked tab to prevent the joint rotating.

Cheers,

Terry

[Les Welsher]

This problem should be of great concern to anyone who has build or are building a RH with wishbones.

There appears to be two problems with the bottom ball joint, the ball joint unscrewing from the wishbone and the taper coming out of the hub.

On the first one I think there should be something locking it in place (wishbone drilled and something inserted to prevent it rotating) obviously the shrink fit of the bottom ball joint into the wishbone isn't working.

The second one must have something to do with different tapers as once the taper of the ball joint is pulled up into the taper of the hub it should be a bugger to get apart again ( have spent lots of time with a ball joint splitter on many cars trying to get them out ).

Why are the nyloc nuts moving up the thread ?

The only thing I can see to prevent this is by using a castled nut, drilling through the thread and fitting a split pin.

 

From what I have read so far on different posts it is lucky that nobody has had a serious accident.

 

Les.

[Guest TerryBarry]

Hi Les,

Are we sure that the nylocks are backing off ??

I feel that it's more likely that the tapers are settling.

I agree that it's important that this problem is sorted before someone is injured.

Regarding the lower wishbone joint unscrewing itself - How can it be that the joint unscrews a bit each time the car makes a left turn but does not return when it straightens up or turns right.

I regret that I'm only posing the questions

Terry

[Guest Greg]

Sounds dodgy this one, I'm not a 2b owner so have'nt seen the joints anyone fancy posting a pic ? I have maxi ball joints which are bolted into the suspension arm. The screw-in ball joint was used on BL cars for years.... they used to unscrew so were always fitted with tab/locking washers. I had a couple collapse on minis I was driving but they always seemed to let go at low speed (some-one once explained the reason to me, but age seems to be getting the better of my memory).

On metros they used lock tabs and thread sealer, so it seems this problem was evident then, and they gave it a belt and braces solution. Loctite 701 ( I think that's the right no.) will stop the threads moving, but difficult to get out.

[Les Welsher]

Terry,

Andy said that the taper was out and it was only hanging on by two threads,

this seems a bit more than going loose on the taper, the nut must have moved. (maybe by friction as the wheel swivelled back and fore)

As far as the bottom unscrewing from the wishbone, when anything vibrates it tends to come loose, (thats why we use shake proof washers)

All I can say is I will be attacking my ball joint with a drill and some pins to make sure this doesn't happen to me.

 

Les

[Guest Ant]

I'm a bit confused about the proposed solution to the ball joint unscrewing itself from the wishbone. Can someone who's modified theirs post a pic please?

 

Thanks

Ant

[Guest Angel Boy]

I am glad that the post has created this debate and that a solution may comeout of it. It was shocking to think that I was chucking the car around the day before and the ball joint was about to drop out.

 

To confirm the tapered part of the ball joint had dropped out of the hub. The threaded part of the taper was no longer in contact with the plastic part of the nyloc (the locking bit in effect).

 

I have made sure that the plastic bit of the nyloc is now well and truely in touch with the threaded part (two clear threads showing). I can imagine it is going to be hell to try and seperate them again

 

As has been pointed out it was probably due to the "settling" of the taper that this has happened. I think I maybe investigating a source of castlated nuts and split pins for the future. Alternatively it may just be the case of checking with a spanner every other week to make sure all it nipped up.

 

Andy

[Guest SteveL]

I'm a little confused by this "settling" of the taper. Surely it's a metal part, which meets another metal part? Unless I've completely mistaken, what's to "settle"? As long as the nyloc on top of the ball joint is tight, I don't see what can move?

 

The only thing I can think of is that the top nyloc comes undone as a consequence of the ball joint itself screwing out of the wishbone, and the nyloc staying still. If this is the case, making sure the wishbone stays put should stop the other problem?

 

Steve

[Les Welsher]

Steve,

I think you are right as far as the taper locking in place is concerned otherwise every new production car would be back in to garage after a few hundred miles to have all it's nylocs retightened on the hubs and steering. The problem here seems to be the taper on the ball joint not being the same as the one in the hub (different manufacturers) therefore it is only gripping on a small portion of the taper instead of the entire length.

As far as curing one problem to solve the other I don't think it will work as the ball joint itself can rotate so the top can move independant of the bottom, if you fix the bottom the top can still come undone and vice versa.

 

Les

[Guest SteveL]

Hi Les

 

Thanks for explaining. Looks like a bit of a problem if this is the case! I'll have to keep any eye on my balljoints once I get on the road!

 

Steve

[Guest DaveB]

Hi Guys

 

Although I am light years away from finishing my car I believe we need to get some conclusion on the problems with the wishbone set up. I have read posts on two problems one where the ball joint nylocs are coming loose and a second where the bottom ball joint screwed into the lower wishbone plate (whilst hot) works loose. The first is a mystery to me Nylocs just don't come undone as previously mentioned and when tapers are tightened there a sod to get out without force. The only solution to this is to fit a castle nut and pin but these went out with the ark so should we have to revert to such old fashioned technology. The bottom ball joint is a different story there is a need to find a way of locking the heat shunk thread into the plate I will have a look later to see I can find a way. If we think about both problems the cause should be similar the taper must lock off the rotation of the ball joint spindle in one direction and not the other that implies that it is not tight enough or it's the wrong taper. Can someone post a picture to open this discussion up further before someone gets hurt.

 

Cheers

 

Dave

[Guest Daz]

The taper working out of the taper joint after the Nyloc nut had come loose is what happened to me in Le Mans last year. Big Jim and Irish Bob will testify to this happening - Irish Bob was a passenger in the car at the time, and afterwards he wouldn't go near it. Like me, I think he doubted my car assembly techniques.

 

Now that I see that the problem is more widespread I am wondering if anyone has approached Robin Hood Engineering to see what they have to say on the matter. I would hate to think of someone having a serious accident caused by something that is a known problem. How it is actually happening I cannot say; it still confuses me to this day, but the simple fact is that for some reason the ball joints are throwing nyloc nuts and the tapers are coming out. Thankfully, so far, all the incidents have been at low speeds.

 

Daz

[Mitch]

Hi All

Checked mine today and all seemed well (1,200mls and 8 weeks) since SVA.

Did notice there were only 2-3 threads threw the nyloc nuts, i did put large washers underneath to spread the load but i don't think that would stop it from happening.

Is there a link in the supplied batch, what month are the problem ones from?

My kit was collected Dec 2001 is that helps.

Hope nobody else suffers from this as it could be very risky at speed.

May try and get some thinner nyloc's so more thread is threw.

But will be keeping a close eye on them from now.

mitch

[Les Welsher]

This is my theory on what is happening to the nyloc on the bottom ball joint.

Firstly, the tapers of the ball joint and the hub are of different angles so instead of the ball joint taper gripping all the way along it's length in the hub it is only gripping on a portion of it. After a few hundred miles of turning the front wheels with associated vibraions the ball joint taper starts to turn in the hub. Once it stops gripping inside the hub, the force of the coilover pushing down on the lower wishbone arm keeps the nyloc nut tight against the top of the hub, when the wheels turn to the left the hub rotates on the balljoint but the nut turns with the hub due to friction effectively unscrewing the nut.

On the sierra front suspension the spring pushes down on the hub where the top dummy strut now is and forces the the taper of the bottom ball joint into the hub. On the wishbone set up, the coilover pushes down on the bottom wishbone which tries to force the taper out of the hub.

 

I hope this lot makes sence as it is hard trying to explain writing it down.

 

Anyhow, a pic of the joint as requested.

 

 

Les