I've now changed the whole passenger side wishbone assembly however I can't get the bottom ball joint to seat properly. I can't get the nut to tighten anymore but there's still about 1/8' to go. I've tried a bit of leverage - all I've managed to do is break my spanner.
Any ideas please?

Is there any thread showing under the nut?

I wonder if it's a pattern part and the threads aren't quite long enough?

I had trouble with a generic drive shaft last week, ended up "machining" some metal off with my grinder.

Anyway, there are two choices, if the thread is too short, stick a washer on before you put the nut on.

If the nut is spinning, I usually put the jack under the hub and crank it up a few inches to put more weight on it.

As for spanner breakage, I am assuming they were generic "not very expensive" type spanners???

Try a Halford's Premium. They come with a lifetime warranty (at least they did....) so are a bit better made, lower carbon content.

If you were in the Inverness area, I could help, but since I can't see the problem.....

Nylock nuts go tight, but not "that" tight. It isn't cross threaded is it?

Thanks for the reply. The nut isn't cross threaded (first thing I checked). I tried the jack under the hub with no joy. The spanner was part of a cheapish Halfords set I bought when I had my first car (1978). I did have a 4 foot length of scaffold tube on it when it broke. I did wonder about the thread not being long enough but I'll have to take it off again to check. With the amount of force I've used to get it on, taking it off should be quite interesting.

I've no idea how the smiley face happened. I typed 1978.

What did Halford's know about spanner's in 1978

I should have thought a 4 foot pole would exert more than enough force to tighten a nut

Definitely a problem. Mind you, could have sheared the ball joint....

Something is amis