I'm using mini front hubs on my current project, to which I've fitted new ball joints. I had a problem with one of the wheels being very stiff to turn. It would go if you pushed hard enough. It turns out that the ball joint pin was binding with the screw on cup and loosening the cup when turned.

for those who don't know. the taper pin has a ball on the end that sits on the hub. a big cup screws on the whole thing.

It is assembled with the small cup sat on the spring on the upright. It has the supplied washers under the cup and I've added yet more grease to be sure. when the cup is little more than finger tight, the pin binds solid. I've run a finger over the faces of the ball and cup and both are smooth.

What have I done wrong? How can I fix it?

Hi,
You need to fit more shims in to create more clearance i have spare shims if you cant get any. Aslo meany to add you are supposed to assemble them dry first.
Cheers

[Edited on 4/5/08 by Shogun969]

As said you have to play about with different thicknesses of shims under the cup untill the pin just moves side to side with hand pressure with it locked up tight. It's a bit harder to get it right on the top one as the spring makes it feel right even when there's play.Take out shims untill it locks then put back thin ones untill it moves.

If you need more shims u2u me and I'll see if I've still got a box full (we used to save the extra ones) and post you some.

adrian

Thanks guys. I'll check them after I get back from Stoneleigh tomorrow. Sounds like I haven't broken them which is good news.

As said above you will probably have to use shims. Here is a pic of the balljoint kit showing the shims you get with it

The mistake you have made is fitting the spring to the top ball joint, it should not have one (which should be clear if you think about the suspension forces experienced by the top ball joint).

The spring is fitted only under the small cup in the bottom ball joint which does not support any weight.

The spring may be only in the lower ball joind then. I didn't remove the small lower cup to check the spring behind it.

I've found the old spacers that I took off when stripping it down. I tried to get a 1.5" spanner from Stoneleigh today. Couldn't find one. Asked for a 1.5" socket but didn't check the size and its a 1 13/16 so can't tighten the thing up still, it seems much better, as tight as I've got it. Thanks again.

PS, Anyone want a 1 13/16 impact socket?

I bought a special ball joint socket for minis when I had mine, I'm sure they are still available. They are deeper than standard to allow for the threads and they also fit the flywheel nut. Here's one on ebay. A cheaper one on Toolmania

[Edited on 5/5/08 by Peteff]