32 replies to this topic

[MK1russ]

I'm in the process of building up the hubs on a Cooper S disc conversion kit and i've spent the best part of today shimming the ball joints.

 

This is the first time i've ever fitted fitted/shimmed mini ball joints, so i'm not exactly sure how the ball joints should feel when correctly fitted and torqued up etc.

 

I'd done a fair bit of research beforehand and decided to not fit the ones supplied with the kit (didn't seem to be of good quality) and sourced a set of genuine Quinton Hazel ones. I've then lapped in all the joints with fine valve grinding paste for 5 mins per joint (this made them a lot smoother) and then thoroughly cleaned them and then begun the process of shimming them.

 

Now i've had a good search through the threads on this forum, other mini forums, google and my Haynes/Mini manuals there just seems to be conflicting answers as to how tight ball joints should be.

 

Haynes just says 'slight resistance should be felt', random Mini manual says '0.003" to no nip?'.

 

Lots of people say they should be so tight that they can only be moved by putting a ring spanner over the end of the pin, i've tried this but it just seems far to tight to me?

 

Some people say you should set them so you can 'just about' move them by hand but i've found setting them like this caused them to be tight in certain spots and loose on others.

 

However a couple of people say that they set them so that they have no up and down play/free float but can be easily moved by a finger.

 

I'm really not sure what advice to follow now as there seems to be no definite answer but as ball joints are a critical suspension part resulting in serious consequences if not properly installed, i want to get it right!

 

I have currently set them so they have no up or down play at all but move easily and smoothly with one finger in all directions and torqued them up to the correct setting. I have't bent up the lock tabs yet until i have a better idea as to how they should be.

 

Thanks in advance 

 

[nicklouse]

ring spanner is too tight.

 

thumb is good.

[Swift_General]

Sounds like you are probably about there with how you describe. The factory manual gives up to 3 thou play, so what I do when I have reached what you describe is re shim with 3 thou less. If the joint then binds you know that you must have had less than 3 thou play pteviously, so within tolerance, so revert to that and job done.

[tiger99]

Follow the Rover manual exactly. Too tight is potentially lethal as either the pin will fracture at its narrowest point or the dome nut will come off its threads after an unpredictable time due to fatigue. No nip is very important, but you can do better than 3 thou with care.

If you can't get it just right by shimming, use a carpenter's oil stone to rub a thou or so off the back of the ball seat to make it looser, or off the shim face of the dome nut to make it tighter.

[MK1russ]

Thanks for the advice everyone.

 

I'd had another go today and think i've got it right now. I had 3 thou shims fitted under all the joints, so i removed them, torqued them up and they all went tight. I then refitted the 3 thou shims so they had no play but could all be wiggled easily and then proceeded to sand down the bottom of all the dome nuts.

 

The joints are now slightly tight. They stay in the upright position now (they slowly fell under their own weight before) and can be pushed in all directions with thumb pressure, going a bit looser as they come to the edges.

 

Sound about right?

[tiger99]

I would say that you are very close indeed to the ideal, and loose enough to be safe, so no need for any more action.  Well done!

[Magneto]

My read on it was if you can move it with a bare hand it's too lose, but if you can move it with a gloved hand, it's just right.

[Spider]

My take on 'no nip' means just that, ie, the ball joint should be able to move withing it being 'nipped'. Given they are all steel on steel parts withing, and no 'loading' from a urethane seat (for example), there is I believe best to be some clearance rather than 'nipped'. When they are nipped, the grease only gets wiped off from where it's needed.

 

There is of course the spring under the lower seat, however, the advice is to adjust the joint without the spring first, then take it apart and fit the spring. The spring is fitted under this seat only, as it can become unloaded (unlike the top one) and 'rattle'.

 

I usually set them such that there's no measurable or 'feelable' play, yet will fall under their pin's own weight. The Torque setting on the cup has a range from 70 to 80 ft / lb and this is to get that very fine adjustment that is beyond the range of the shims.

 

There's probably a zillion different takes on how they should be, but I think we all agree that they should not be tight.

[racingbob]

So the bottom one is done same as top then add the spring but that makes them realy tight

[tiger99]

Racingbob, Just make very sure that it goes back to the same torque setting after adding the spring. Use a marker pen (NOT a scriber or punch!) to make alignment marks on the nut and hub. And also, as there have been some incorrect parts around, check that the spring is not too long and going solid. If in the slightest doubt re-fit the old spring, they do not wear out. New parts feel tight with the spring fitted, but soon loosen off as the working surfaces bed in, even if they have already been lapped.

 

Magneto, what part of "no nip" or for that matter, basic safety, do you not understand? Opinions like that, which have no basis in fact, can easily result in people being killed. Needing a gloved hand is far too tight.

[Dusky]

Try asking a local carpart shop of you van feel a balljoint of a modern car. Thats how tight i set them now. Recently did a corvette c4's balljoints, the feel of those is just as described in our manuals.

[racingbob]

Am finding this bottom ball joint confusing I am not a mechanic if you do the joint without the spring as the top one then add the spring it goes solid or am I missing something here

[imack]

There is of course the spring under the lower seat, however, the advice is to adjust the joint without the spring first, then take it apart and fit the spring. The spring is fitted under this seat only, as it can become unloaded (unlike the top one) and 'rattle'.

I've always done them like this.
The spring will load the ball joint and make it very stiff, but you will still have the ball joint correctly shimmed and it won't be the cap 'clamping' the ball joint, only the spring pushing the ball against the cap.

[Spider]

Try asking a local carpart shop of you van feel a balljoint of a modern car. Thats how tight i set them now. Recently did a corvette c4's balljoints, the feel of those is just as described in our manuals.

 

Yes, but you'll also find these joints are 'loaded' in that they have a spring seat of one type or another. In this regards, the Mini, ADO16 and 1800 series are somewhat unique in that it's only the lower joint that's loaded like this.

 

<EDIT: Hopefully this works;-

 

>

Edited by Moke Spider, 23 June 2017 - 09:33 PM.

[Magneto]

You know, I've read the things you write and for the most part find you quite credible, but I'm really tired of you holding yourself up as the ONLY expert on this forum pal, I've been working on Minis for 50 years, I have never had a ball joint fail from my work, so maybe it's time for you to climb down off your soapbox and give it a rest?

 

"No nip" is not exactly a technical term is it? As such it's also open to interpretation as much as any other.....

 

 

Magneto, what part of "no nip" or for that matter, basic safety, do you not understand? Opinions like that, which have no basis in fact, can easily result in people being killed. Needing a gloved hand is far too tight.

Edited by Magneto, 25 June 2017 - 05:45 AM.