Only ever had to replace one set of upper wishbones in three 156's I've owned.... That's in about 95,000 miles total between the three...
There isn't one!
Just common sense and a little bit of knowledge I learned in my apprenticeship
I'll keep it short:
Use a hyperdermic syringe filled with silicon lubricant.
Push the needle in as far as you can & inject into the outer edges of the bushes as soon as they start creaking (listen to your Alfa, more often than not, it will tell you what is going wrong)
.... Not six month later when you can be bothered! It's far too late by then as the damage is done...
Rubber vs alloy
, what's going to win a friction contest?
The idea is to lubricate the bush so it doesn't get the chance to shrink (which causes the friction), crack and then perish... Job done and it isn't difficult.... Total cost £ 5.00
and you can use the silicon lube on many other items and parts etc.
How it works:
it feeds the rubber and swells it back up to original size, as Del boy says "a little dab will do ya"
Or you can replace the upper arms every 24,000 miles, your choice at £££'s
I know what I prefer to pay!
I do this every six month and you can also do the anti-roll bar bushes the same way while you are on!
Prevention is far better than the cure..... Isn't it?
All three 156's have had the same treatment, all three have passed multiple MOT's with no issues from the bushes or arms and they don't ever squeak!
As far as siezed ball joints
: The same method can be used into the rubber boots with some plusgas injected in, let it do its job then simply reverse the process using the vaccuum of an empty syringe to suck it all back out.
Then re-inject using the correct grease, give it a good wiggle on full range of motion. Mark the hole you made with some chalk.
Then rub some vulacanising fluid from a bicycle puncture repair kit to seal the pin hole you made.
I'll let you guys decide whats best on your own alfa's