Removing ball stud for rocker arm

[col320ce]

I'm onto the 230SL now doing the tappets. One of the ball studs is very loose so I'm replacing it.  I have a good used one form a previous engine rebuild.  To remove the larger bit that actually screws into the cylinder head takes a lot more force that I think it should.  Am I doing something wrong or should it just screw out?

The bit circled in the photo is the bit I'm trying to remove (this is the replacement one).

Thanks!

[stickandrudderman]

Just replace the ball post and leave the base part where it is. They have a tendency to pull the thread out if you have to use too much force.

[col320ce]

Unfortunately it is the base that is the problem. The new post is still loose if I re use the base...

[mbzse]

.../...The new post is still loose if I re use the base...

Some useful tips for instance in this posting:
https://www.sl113.org/forums/index.php?topic=28063.msg203177#msg203177

[MikeSimon]

I was heavily involved in the thread Hans is referring to. I had the same problem when I installed new ball studs. I was not able to remove the bases and some of the new ball studs remained loose. I distorted the threads of the new ball studs ever so slightly with a press/vice and achieved the necessary increase in torque. Be careful doing this.

[col320ce]

I read that thread... It was really useful. I'll try doing the same. I have plenty of spares if I muck up.
Thanks!

[col320ce]

I deformed the inner part by putting it in a vice. Not surprisingly I had to crank a fair bit of pressure on it.
But worked a treat!

[Aaron h]

Be sure you put thread sealant on the threads of the lower parts that screw into the cylinder head.  If not then oil will start leaking from the bottoms of them, down the cylinder head, and makes an unsightly mess (on the left side of the head).  On the right side of the head the oil would escape through the exhaust and you'd never know.