28 replies to this topic

[GreenMini17]

Spent most of today trying to replace the top and bottom ball joints on a front hub. Rather tedious job i may say. Following the 'haynes manual' i cannot get the right feel in them. The top one is not too bad. A little binding, then it loosens up, then binds up again. But the bottom one (with the tension spring) is a right pain. I got it spot on with the amount of shims without the spring in place, then i greased it all up, put it all back together (spring included) and its solid. Is there any special way for this to be done?

Edited by Chris-G, 29 December 2012 - 05:29 PM.

[mike.]

Have you tried lapping these joints in at all? The poor quality of joints you get now means they have high and low spots which prevent you from getting a consistent feeling from them when shimming.

The bottom joint, you need to shim it without the spring fitted and only fit the spring on final assembly.

Once the spring is in and the joints are greased, you won't be able to move them by hand.

[GreenMini17]

No i havent lapped them, but this makes sense now you mention it! I will have them out again and do so.

On first shimming excersice i didnt fit the spring. Then once i greased up for final assembly i did fit it.

So both top and bottom joints should be solid once greased and tightended up? Correct?

[Joe-C]

this video might help:

[tiger99]

No! That is dangerous, as fatigue fracture is VERY likely if they are too tight. The top joint will ALWAYS move freely by hand. You can assemble with 3 in 1 oil or similar, just to provide some lubrication during assembly. When you pump it full of grease, any residual end float will disappear but it should not become tight.

The spring does complicate the bottom joint, as it spoils the feel, and it is essential that when setting the shimming that the ball cap nut must go back finally to EXACTLY the same place, which means torquing up accurately every time, and preferably making marks on the hub, locktab and ball cap so that you can also see that it went back to exactly the same place.

The Rover manual, which is the ultimate authority, requires the setting to be between no nip and 3 thou endfloat, with a 3 thou shim to be added if in doubt. I have always set them up like that, what some people might call loose, and they always lasted at least 60k miles, and never, ever a breakage.

[GreenMini17]

As per usual with 'everyones opinion' im totally confused. What does "between nip and 3 Thou end float mean"? It sounds incredibly accurate, something that surely cannot be acheived with these bastard things?

Edited by Chris-G, 29 December 2012 - 08:06 PM.

[tiger99]

It can very easily be achieved as the thinnest shim is 3 thou, and if you need finer adjustment you rub the flat face of the ball cap on something like a carpenters oil stone, or a sheet of abrasive paper on a very flat surface, to remove maybe a thou and so make it tighter. Or take the ball seating out and rub the back of it to make it looser. (Not to be confused with lapping the running surfaces,which you should do first if they need it.)

It only takes a reasonable degree of patience, and a modest amount of time.

[GreenMini17]

Thank you, that makes a little more sense now. What i initially thought was 'an easy job' turns out, as usual, is very time consuming! Thanks for your replies

[A-Cell]

It's called 'Fitting' as opposed to assembling. That's how it is with 50 year old design.Today's designs just require assembly, no real skill required in Service.

[tiger99]

Good point! Which is why the Metro went for sealed ball joints. Typical mechanics were no longer able to "fit" things, as in the old days. Skills are being lost, like hand scraping of white metal bearings in very old engines. They still do it on steam locos, I believe, but on new build (Tornado) they went for mass produced roller bearings. But properly "fitted" parts can last longer, usually at least. And, if you "fit" things, even in a fairly basic way such as matching head and manifold ports by grinding with your Dremel, and correctly gapping piston rings by use of a small oil stone, things actually work better than if you just throw them together.

You may wish to consider why the rear radius arms have one mass-produced, very precise and fairly easily replaced needle roller bearing, and one plain bush which needs "fitting".

[icklemini]

not sure its anything to do with the competance of the mechanic.. its all about time money and efficiency.
its quicker and easier to produce and fit the sealed units at production rather than spend time 'fitting'...

wonder how long it took rover to assemble a 'metro' hub complete vs a mini hub...

[A-Cell]

Actually the main reason Metro went to sealed Ball Joints to increase the Service Interval compared with Mini. From 6000 Mles to 10,000 miles. In the specific case of the Ball Joint, the objective was to eliminate the re-greasing. Assembly time of the sub assemblies was secondary.
The same applies to all the mods introduced at that time, some were trialled on the Mini before Metro intro and some applied to Mini after Metro launch (8th October 1980).
E.g. Verto clutch, no adjustment required as the friction plate wears.
It was deemed impractical to use Metro hubs on Mini because the geometry differences would have meant costly changes to suspension arms, tie bars and wheels.

[icklemini]

point I were making.. is that things rightly or wrongly move on... make it easier.. cheaper and quicker.. as you say the increased service intervals for the metro is a good example.

though greasing a ball joints at a service takes seconds at the dealership and has a negligible cost.. where saving 30mins in assembling hubs at the factory is in comparison big money...

I cant think of any modern car that doesnt have 'disposable' parts that generally just need replacement.. rightly or wrongly..its cheaper!

Edited by icklemini, 30 December 2012 - 09:20 PM.

[A-Cell]

Absolutely. I think we are in agreement.
Part of the joy of classic car ownership is the engineering skills required. Happy new year.

[BVY]

I was told by one of the minispares guys to have them shimmed up so you can't move them by hand but you can move easily enough them with a ring spanner. Worked fine for me.

I never want to do ball joints again though! It took me hours just un-doing the ball joint domes. All 4 of them were so stuck that bouncing all my weight (12st) on the end of a 2' bar wouldn't budge them!
At least they're all good now...